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Transcript of c++ chapter 3
CHAPTER THREECHAPTER THREEAn Overview of C++An Overview of C++
PART ONEPART ONESimple ProgramsSimple Programs
3.1.1 Your First C++ ProgramBefore getting into any theory, let’s look at a simple C++ program.
Example(1)Example(1)Program #1 – A first C++ programProgram #1 – A first C++ program..**//
Enter this program/, then compile and run itEnter this program/, then compile and run it..
/*/*
include <iostream.hinclude <iostream.h<<# #
include <conio.hinclude <conio.h<<# #
main ( ) is where program execution beginsmain ( ) is where program execution begins.. // //
( ) ( ) int mainint main
{{
;";" . .cout << "This is my First C++ Programcout << "This is my First C++ Program
getchgetch; ( ); ( )
return 0return 0; ;
}}
When run, this program displays the following text on the screen:
. This is my First C++ Program
Before we continue, it is necessary to define two terms.
source code:
which is the version of your program that humans can read. The preceding listing is an example of source code.
Object code or executable code :
which is the executable version of your program (source code) and it is created by the compiler when it compiles your program.
Object
Code
Source
Code
C++
Compiler
Exercise:Write a C++ program to print the following statement on the screen
" Hi, my name is Saied , What is your name"?
3.1.2 A second simple program
Example( 2)
The following program creates a variable called value, gives it the value 1023, and then display the message "This program prints the value: 1023" on the screen.
// //program #2 –using a variableprogram #2 –using a variable
include include < iostream.h< iostream.h<<##
# #include < conio.hinclude < conio.h<<
int mainint main( ) ( )
{{
int value ; // this declares a variableint value ; // this declares a variable
value = 1023 ; // this assigns 1023 to valuevalue = 1023 ; // this assigns 1023 to value
cout << " This program prints the valuecout << " This program prints the value;"=;"=
cout << value ; // This displays 1023cout << value ; // This displays 1023
getchgetch;( ) ;( )
return 0return 0;;
}}
The output of this program is:
This program prints the value = 1023
3.1.33.1.3 A more practical exampleA more practical example
Example( 3)Example( 3)
Write a program to convert gallons to litersWrite a program to convert gallons to liters
( (gallon = 4 litersgallon = 4 liters))
The program: //This program converts gallons to liters.
#include < iostream.h< #include <conio.h<
int main ( ) {
; int gallons , literscout << "Enter number of gallons;": cin >> gallons ; // this inputs from the user
liters = gallons * 4 ; // convert to liters ; cout << "Liters = " << liters
}
getch;( ) return 0;
The output is:
Enter number of gallons: 10
Liters = 40
3.1.43.1.4 A Quick ReviewA Quick ReviewLet us review the general form of a C++ programLet us review the general form of a C++ program..
# #include < iostream.hinclude < iostream.h<<
# #include <conio.hinclude <conio.h<<
( )( ) int mainint main
{{
int … , … ; // integer data typeint … , … ; // integer data type
typetype float … , … ; // floating point datafloat … , … ; // floating point data
; ; .………… .…………
; ; .………… .…………
; ; .….…………………
coutcout; -------- >>" ">>; -------- >>" ">>
getchgetch;( );( )
return 0return 0;;{{
ExercisesExercises::11 - -Explain the above program. And use float value instead of Explain the above program. And use float value instead of
integer valueinteger value
22 - -Write C++ program converting US dollars)$( to Egyptian Write C++ program converting US dollars)$( to Egyptian poundspounds
( (1$1$==5.525.52 Egyptian poundsEgyptian pounds))
33 - -Write C++ program converting Egyptian pounds to US dollarsWrite C++ program converting Egyptian pounds to US dollars
( ( $ $ 0.10.181159428115942 ((1Egyptian pound1Egyptian pound==
44 - -Write C++ program converting Kilo Bytes to BytesWrite C++ program converting Kilo Bytes to Bytes
( ( 11 K.B. = 1024 BK.B. = 1024 B) )
55 - -Write C++ program converting Mega Bytes to Kilo BytesWrite C++ program converting Mega Bytes to Kilo Bytes
((11 M.B.= 1024 K.BM.B.= 1024 K.B
6 -Write C++ program converting Gega Bytes to Mega Bytes
(1G.B. = 1024 M.B.)
7 -Write C++ program converting Tera Bytes to Gega Bytes
( 1T.B. = 1024 G.B.)
88 - -Correct the following statements if it has errors according Correct the following statements if it has errors according to C++ rulesto C++ rules..
/* /*commentcomment */ */
Correction is : Correction is : /*/* comment comment */*/ OR OR ////commentcomment
// ??????????*/// ??????????*/
Correction isCorrection is ??????????*/ : ??????????*/ : /*/*
But this correction is wrong: ?????????? // whyBut this correction is wrong: ?????????? // why!!!!!!
*/AAAAAA/**/AAAAAA/*
Correction is : Correction is : /*/*AAAAAAAAAAAA*/*/ OR OR ////AAAAAAAAAAAA
include <iostream.kinclude <iostream.k ; < ; <
Correction is: Correction is: ## include <iostream. include <iostream.hh<<
* * include <iostream.hinclude <iostream.h<<
Correction is: Correction is: ## include <iostream.h include <iostream.h<<
# #include <iosteram.hinclude <iosteram.h ;< ;<
Correction is: # include <iostCorrection is: # include <iostreream.ham.h<<
# #inklude <isotream.hinklude <isotream.h;<;<
Correction is: # inCorrection is: # incclude <ilude <iosostream.htream.h<<
# #include>conio.kinclude>conio.k>>
Correction is: # include Correction is: # include <<conio.hconio.h <<
int mainint main
Correction isCorrection is: int main: int main( ) ;( ) ;
ind main[ ] ;ind main[ ] ;
Correction is: inCorrection is: intt main main( ) ( ) ;;
int mainint main;} { ;} {
Correction is: int mainCorrection is: int main( )( ); ;
int mainint main( ) ( )
Correction is: int main( ) Correction is: int main( ) ;;
int mainint main ( ) ( )
Correction is: int mainCorrection is: int main ( ) ( );;
return oreturn o ; ;
Correction is: return Correction is: return 00 ; ;
return 0return 0 , ,
Correction is: return 0Correction is: return 0 ;;
return 0return 0;;
The statement is correct The statement is correct
gtchgtch ( ) ( )
Correction is : gCorrection is : geetchtch ( ) ( );;
getkhgetkh ; ( ) ; ( )
Correction is : getCorrection is : getcchh ; ( ) ; ( )
getchgetch ,( ) ,( )
Correction is : getch ( )Correction is : getch ( );;
getch ( );getch ( );
The statement is correctThe statement is correct
cout<"Hicout<"Hi ," ,"
Correction is : cout<Correction is : cout<<<"Hi"Hi " " ; ;
cout << "Hi";cout << "Hi";
The statement is correctThe statement is correct
cout << "Hicout << "Hi ; ;
Correction is : cout << "HiCorrection is : cout << "Hi"" ; ;
cout <<"Hicout <<"Hi ;" ;"
The statement is correctThe statement is correct
cin <<gallons;cin <<gallons;
Correction is : cinCorrection is : cin>>>>gallons;gallons;
cim>>gallonscim>>gallons ; ;
Correction is : ciCorrection is : cinn>>gallons>>gallons;;
cin>>gallons;cin>>gallons;
The statement is correctThe statement is correct
99 - -Correct the following C++ program and find its output as Correct the following C++ program and find its output as the computer dothe computer do..
# #include<iostream.hinclude<iostream.h<<
# #include<conio.hinclude<conio.h<<
( ) ( )int mainint main
int valueint value; ;
value = 100value = 100; ;
;; cout << cout << "" value = value = "" value value
; ( ); ( ) getchgetch
;; return 0return 0
The correction of (9)
#include<iostream.h< #include<conio.h<
) (int main {
int value ; value = 100;
; cout << " value = " <<value ; getch) ( ; return 0
}the output is value = 100
PART TWOPART TWOFUNCTIONSFUNCTIONS
A C++ program is constructed from building blocks called functions .
A function is a subroutine that contains one or more C++ statements and performs only one task .
Each function has a name that is used to call it.
In general, you can give a function whatever name you please .
Remember that there are words reserved for C++ built in functions such as main . ) (
You do not use the reserved words as a function name but you can change the reserved word )deleting some letters or adding some letters( before use it.
3.2.1 A Program with Two Functions3.2.1 A Program with Two Functions
The following program contains two functions : The following program contains two functions : main( ) and myfunc( ).main( ) and myfunc( ).
Before running this program, examine it closely Before running this program, examine it closely and try to figure out exactly what it displays on and try to figure out exactly what it displays on the screen.the screen.
Example(4)
*/ This program contains two functions :main( ) and myfunc( )
/*
# include <iostream.h<
# include <conio.h<
void myfunc;( )
int main( )
{
cout <<"In main;" ( )
( ) myfunc( ) ; // call myfunc
cout<< " Back in main;"
getch;( )
;; return 0return 0
}}
void myfuncvoid myfunc( ) ( )
{{
cout << " Inside myfunccout << " Inside myfunc;" ( );" ( )
}}
The program works like this .
First, main) ( begins, and it executes the first cout statement .
Next , main ) ( calls myfunc .) (
Next , myfunc) ( executes its cout statement, and then returns to main ) ( at the line of code immediately following the call .
Finally, main) ( executes its second cout statement and then terminates .
The output on the screen is this:
In main ) ( Inside myfunc) ( Back in main) (
As you can see, myfunc) ( does not contain a return statement and does not return a value .
In C++, functions that don’t return values are declared as void.
3.3.2 Function ArgumentsIt is possible to pass one or more values to a function.
A value passed to a function is called an argument.
In the programs that you have studied so far, none of the functions) main) ( and myfunc) ( (take any arguments .
However, functions in C++ can have one or more arguments .
The upper limit of an arguments number is determined by the compiler you are using, but Standard C++ specifies that a function
must be able to take at most 256 arguments .
When you create a function that takes one or more arguments, the variables that will receive those arguments must also
declared .
These variables are called parameters of the function.
Example(5)
//A simple program for a function of two arguments.
#include<iostream.h<
# include<conio.h<
void mul (int x , int y):
int main( )
{
mul (10,20);
mul (5 , 6);
;( mul (8 , 9
getch;( )
return 0;
}}
void mul (int x , int y)void mul (int x , int y)
{{
cout << x * ycout << x * y;" ">>;" ">>
}}
This program will print 200, 30 and 72 on the screen. When mul( ) is called, the C++ compiler copies the value of each argument into the matching parameter. That is, in the first call to mul( ), 10 is copied into x and 20 is copied into y. In the second call, 5 is copied into x and 6 into y. in the third call, 8 is copied into x and 9into y.
REMEMBER:The term argument refers to the value that is used to call a function. The variable that receives the value of an argument is called a parameter.
3.2.33.2.3 Functions Returning ValuesFunctions Returning ValuesMany of the C++ library functions that you use will return Many of the C++ library functions that you use will return values. Functions you write may also return values to the values. Functions you write may also return values to the calling routinecalling routine..
In C++, a function uses a return statement to return a value. In C++, a function uses a return statement to return a value. The general form of return is: Return valueThe general form of return is: Return value;;
Where value is the value being returned . To illustrate the Where value is the value being returned . To illustrate the process of functions returning values ,the last program can be process of functions returning values ,the last program can be rewritten as shown next . In this version, mul( ) returns the rewritten as shown next . In this version, mul( ) returns the product of its argumentsproduct of its arguments..
Example(6) //Returning a value
#include<iostream.h<
#include<conio.h<
int mul (int x , int y);
int main( )
{
; int answer
answer = mul( 10 , 11) ; // assign return value
cout<< "The answer is " << answer;
getch;( )
return0;
{{
// //This function returns a valueThis function returns a value..
int mul ( int x , int y)int mul ( int x , int y)
{{
return x * y ; // return product of x and yreturn x * y ; // return product of x and y
}}
The output of the program isThe output of the program is::
The answer is 110The answer is 110
Example(7)Write C++ program which containing 4-functions for addition ,
subtraction, multiplication and division of two numbers x , y.
The program #include<iostream.h<
#include<conio.h<
; int add (int x , int y)
; int sub (int x , int y)
; ( int mul (int x , int y
int div (int x , int y);
int main( )
{
int answer;
answer = add (10 , 2);
; cout <<" answer+ = " << answer
answer = sub (10 , 2);
; cout << " answer- =" << answer
answer = mul (10 , 2);
cout << " answer* = " << answer;answer = div (10 , 2);
; cout << " answer/ = " << answergetch;( )
; return 0 }
( int add ( int x , int y {
; return x+y }
int sub ( int x , int y) {
; return x-y }
int mul ( int x , int y) {
; return x*y }int div( int x , int y) {
; return x/y }
The output is:
answer+ = 12 answer- = 7 answer* = 20 answer/ = 5
3.2.4 Some Output Options
To put a new line character into a string, use this code: \n )a backslash followed by a lowercase n(.
Example(8)To see an example, try the following program.
*/This program demonstrates the \n code, which generates a new line/*.
#include<iostream.h<
#include<conio.h<
( ) int main
{
;" cout << "one\n
;" cout << "two\n
;" cout << "three
cout << "four;"
getch;( )
return 0;
}
This program produces the following output:
one
two
threefour
Example(9)Write C++ program which prints the statements Hi ,My name is Saied, What is your name?. Each statement in a separate line.
The program#include<iostream.h<
#include<conio.h<
int main( )
{
cout << "Hi\n; "
; " cout << "My name is Saied\n
cout << "What is your name; "
; getch( )
; return 0
}
Example(10)Write C++ program which containing 4-functions for addition, subtraction, multiplication and division of two numbers x , y.
The program #include<iostream.h<
#include<conio.h <
;( int add (int x , int y
; ( int sub (int x , int y
; ( int mul (int x , int y
int div (int x , int y);
int main( )
{
int answer ;
answer = add (10 , 2);
cout <<" answer+ = " << answer;
;( answer = sub (10 , 2
cout << "\n answer- =" << answer;
; )10 , 2 (answer = mul
; cout << "\n answer* = " << answer
answer = div (10 , 2);
; cout << "\n answer/ = " << answer
getch;( )
return 0; }
}
( int add ( int x , int y
{
return x+y;
}
int sub ( int x , int y)
{
return x-y;
int mul ( int x , int y)
{
; return x*y
}
int div( int x , int y)int div( int x , int y)
{{
return x/yreturn x/y;;
}}
Guess its outputGuess its output??
Exercise: 1 -Write a program which displays the following figure on the screen
* * *
* * *
* * * * * *
* * * * *
* * * * * *
* * * * * *
2 -Discuss the following program and find its final outputa) #include<iostream.h<
# include<conio.h<
int main ( )
{
cout << "one\n \n";
cout << "two\n \n";
"; cout <<"three\n \n
cout << "four\n \n";
getch;( )
; return 0
}
b) #include<iostream.h<
# include<conio.h<
int main ( )
{
"; cout <<"\n\n one \n\n
"; cout << "\n\n two \n\n
"; cout << "three\n \n
"; cout << "four\n \n
getch;( )
return 0;
}
PART THREEPART THREEif Statement & for Loopif Statement & for Loop
Conditions, Logical Expressions, and selection Conditions, Logical Expressions, and selection control Structurescontrol Structures
1.1. To be able to construct To be able to construct truetrue and and falsefalse statements statements to evaluate a given condition. to evaluate a given condition.
2. To be able to construct 2. To be able to construct ifif statements to perform a statements to perform a specified task.specified task.
3. To be able to construct 3. To be able to construct if-elseif-else statements to statements to perform a specified task. perform a specified task.
4. To be able to nested 4. To be able to nested ifif statements to perform a statements to perform a specified task.specified task.
5. To be able to design and implemente a test plan.5. To be able to design and implemente a test plan.6. To be able to debug a program with a selection 6. To be able to debug a program with a selection
control structure.control structure.
Conditions, Logical Expressions, and Conditions, Logical Expressions, and selection control Structuresselection control Structures
Condition
TrueFalse Statements
Executed when condition is true
3.3.1 The if Statement3.3.1 The if Statement
The C++ The C++ if if statement operates in much the same way that an statement operates in much the same way that an if statement operates in any other language. if statement operates in any other language. Its simplest form is : Its simplest form is : if(condition) statement ;if(condition) statement ; Where condition is an expression that is evaluated to be either true Where condition is an expression that is evaluated to be either true
or false.or false. In C++, true is non-zero and false is zero. If the condition is true, In C++, true is non-zero and false is zero. If the condition is true,
then the statement will execute. then the statement will execute. If it is false, then the statement will not execute.If it is false, then the statement will not execute. if(10 < 11 ) cout″ 10 is less than 11″ ;if(10 < 11 ) cout″ 10 is less than 11″ ; if(10 < 11 ) x=x+5 ;if(10 < 11 ) x=x+5 ;
The comparison operators:
> Greater than
>= Greater than or equal
< Less than
<= Less than or equal
== Equality
Example(11)The following program shows an example of the if statement. It
prompts the userfor two numbers, and reports if the first value is less than the
second.
// This program illustrates the if statement.#include<iostream.h>#include<conio.h> int main ( ) } int a , b ; cout << ″ Enter first number : ″; cin >> a ; cout << ″ Enter second number : ″; cin >> b ; if( a < b ) cout << ″First number is less than second number ″;
getch ( ) ; return 0 ;{
The output of this program is :
Enter first number : 4Enter second number : 9First number is less than second number
3.3.2 The for Loop
The for loop is used to repeat a statement a specified number of times .
Its simplest form is for ( initialization ;condition ;increment) statement ;
Here, initialization sets a loop control variable to an initial value.
Condition is an expression that is tested each time the loop repeats.As long as condition is true (non-zero), the loop keeps running. Increment is an expression that determines how the loop controlvariable is incremented each time the loop repeats.
Example(12)
The following program prints the numbers 1 through 100 on the screen.
//This program illustrates the for loop statement.#include<iostream.h>#include<conio.h> int main ( ) } int count ; for( count=1;count<=100;count=count+1)cout<<count<<″ ″; getch ( ) ; return 0 ; {
The output is :
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 5051 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
Exercise:Write a program that prints the numbers 122 through 1000 on the screen.
Remark:
count=count + 1 equivalent to count ++
count=count - 1 equivalent to count - -
3.3.3 Blocks of CodesBecause C++ is a structured language, it supports the creation ofblocks of code. A block is a logically connected group of programstatements that is treated as a unit. In C++, a code block is created by placing a sequence of statements between opening and closing curly braces. In this example,
if(x<10) } cout<<″ too low , try again″ ; cin>> x ; {
The two statements after the if and between the curly braces are both executed only if x is less than 10.
These two statements, together with the braces, represent a block of code.
Example(13)The following program uses a block of code. Enter and run the
program so that you can see the effect of the block.
//This program demonstrates a block of code.#include<iostream.h>#include<conio.h> int main ( ) } int a , b ; cout << ″ Enter first number : ″; cin >> a ; cout << ″ Enter second number : ″; cin >> b ; if( a < b ) } cout << ″First number is less than second number.\n ″; cout<<″ Their difference is : ″<<b-a ;
{ getch ( ) ; return 0 ;{
The output is:
Enter first number : 4Enter second number : 9First number is less than second number.Their difference is : 5
3.3.4 Semicolons and PositioningIn C++, the semicolon is a statement terminator. That is, each individual statement must be ended with a semicolon.C++ does not recognize the end of the line as a terminator.
For example, x = y ; y = y + 1 ; mul( x , y ) ;is the same as x = y ; y = y +1 ; mul( x , y ) ;to a C++ compiler.
Exercise:Use the above section in all pervious programs.
PART FOURPART FOURArraysArrays
3.4 ARRAYSThis section discusses the array. An array is a collection of variables of the same type that are referredto by a common name.
In C++, arrays may have from one to several dimensions, although the one-dimensional array is the most common.
3.4.1 One-Dimensional Arrays:A one-dimensional array is a list of related variables.The general form of a one-dimensional array declaration is: type name [size] ;Here, type declares the base type of the array. The base type determines
the data type of each element that comprises the array. name defines the array name. size
defines how many elements the array will hold.
For examples, int sample [10] ;declares an integer one-dimensional array named sample that is ten
elements long.Sample[0] Sample[1] Sample[2] Sample[3] Sample[4] Sample[5] Sample[6] Sample[7] Sample[8] Sample[9]
Where sample[0], sample[1], sample[2], sample[3], sample[4], sample[5], sample[6], sample[7], sample[8] and sample[9] are called the elements of the sample array.
float list [7] ; declares a floating one-dimensional array named list that is seven
elements long.
List[0] List[1] List[2] List[3] List[4] List[5] List[6]
Example(14)The following program loads the array sample with the numbers 0through 9:
#include <iostream.h>#include <conio.h>int main ( )} int sample[10];//this reserves 10 integer elements int t; for (t=0;t<10;t++)sample[t]=t;//load the array for (t=0;t<10;t++)cout<<sample [t]<<" ";//display the array getch( ) ; return 0 ;{
0Sample[0]
1SAMPLE}!{
2Sample[2]
3Sample[3]
4Sample[4]
5Sample[5]
6Sample[6
7SAMLE}7]
8Sample[8
9Sample[9]
In C++, all arrays consist of contiguous memory locations. That is, all array elements reside next to each other in memory. The lowest address corresponds to the first element, and the highest address to the last element.
Example(14.1)#include <iostream.h>#include <conio.h>int main ( )} int sample[10];//this reserves 10 integer elements int t; for (t=0;t<10;t++)sample[t]=9-t;//load the array for(t=0;t<10;t++)cout<<"sample["<<t<<"]="<<sample[t]<<"\n ";//display the array getch( ) ; return 0 ;{
Example(14.2)#include <iostream.h>#include <conio.h>int main ( )} int sample[10];//this reserves 10 integer elements int t; for (t=0;t<10;t++)sample[t]=9-t;//load the array for(t=0;t<10;t++)cout<<"sample["<<t<<"]="<<sample[t]<<"\n
";//display the array getch( ) ; return 0 ;{
Example(15)
The following program creates an array of ten elements, assigns each element a random value, and then calculates and displays its maximum and minimum values.
#include <iostream.h>#include <iostream.h>#include <conio.h>#include <conio.h>#include <stdlib.h>//Header for the function rand( )#include <stdlib.h>//Header for the function rand( )int main ( )int main ( )}} int i, minvalue , maxvalue;int i, minvalue , maxvalue; int list[10];int list[10];
for (i=0;i<10;i++)list[i]=rand( ); //find minimum value minvalue =32767; for (i=0;i<10;i++)if(minvalue> list[i]) minvalue= list[i] ; cout<<"minimum value="<<minvalue<<"\n"; //find maximum value maxvalue =0; for (i=0;i<10;i++)if(maxvalue< list[i]) maxvalue=list[i]; cout<<"maximum value="<<maxvalue<<"\n"; getch( ) ; return 0 ;{
Example(16)Write a program to find the maximum and minimum values for the arraycalled saied with 12 elements such that:
22 4 9 55 1 6 27 15 99 3 -2 51
#include <iostream.h>#include <conio.h>int main ( )} int i, minvalue ,maxvalue; int saied[12]; saied[0]=22;saied[1]=4;saied[2]=9;saied[3]=55;saied[4]=1; saied[5]=6;saied[6]=27;saied[7]=15;saied[8]=99;saied[9]=3; saied[10]=-2;saied[11]=51; for (i=0;i<12;i++)cout<< saied[i]<<" "; //display the array //find minimum value minvalue=100; for (i=0;i<12;i++)if(minvalue> saied[i]) minvalue= saied[i]; cout<<"minimum value="<<minvalue<<"\n";
//find maximum value maxvalue=0; for (i=0;i<12;i++)if(maxvalue< saied[i]) maxvalue= saied[i]; cout<<"maximum value="<<maxvalue<<"\n"; getch( ) ; return 0 ;{
3.4.2Array InitializationC++ allows the initialization of arrays. The general form of array initialization
is Similar to that of other variables, as shown here: type array name [size] = } value list{ ;
Where the value list is a comma-separated list of constants that are type-compatible
with the base type of the array. The first constant will be placed in the first position of the array, the second
constant in the second position , and so on.
In the following example, a 10-element integer array is initialized with the numbers
1through 10 :
int i[10] =}1,2,3,4,5,6,7,8,9,10{ ;This means that i[0] will have the value 1 , and i[9] will have the value
10.
Example(16.1)Use the above notation in example(16)
#include <iostream.h>#include <conio.h>int main ( )} int i, minvalue ,maxvalue; int saied[12]=}22,4,9,55,1,6,27,15,99,3,-2,51{;for (i=0;i<10;i++)cout<< saied[i]<<" "; //display the array //find minimum value minvalue=100; for (i=0;i<12;i++)if(minvalue> saied[i]) minvalue= saied[i]; cout<<"minimum value="<<minvalue<<"\n";
//find maximum value maxvalue=0; for (i=0;i<12;i++)if(maxvalue< saied[i]) maxvalue= saied[i]; cout<<"maximum value="<<maxvalue<<"\n"; getch( ) ; return 0 ;{Example(17)The following program sorts an array of integers (ascending order) thatcontains random values.
// ascending order#include<iostream.h>#include<conio.h>#include<stdlib.h>int main( )
} int nums[10]; int a ,b ,t ,size; size=10;//number of elements to sort for (t=0;t< size; t++) nums[t]=rand( );//loading the array //displaying the array cout<<" original array is : "; for (t=0;t< size; t++) cout<<nums[t]<<" "; cout<<"\n";
//sorting the array for (a=1;a< size ;a++) for (b=size-1;b>=a ;b--)} if(nums[b-1]> nums [b])} //exchange elements t=nums[b-1]; nums[b-1]=nums[b]; nums[b]=t; { {
//displaying sorted array cout<<"Sorted array is: "; for (t=0;t< size; t++) cout<< nums[t]<<" "; getch( ); return 0; {
EXERCISE:Write a program for sorting an array of random integers (descending order) with size 10
// descending order#include<iostream.h>#include<conio.h>#include<stdlib.h>int main( ) } int nums[10]; int a ,b ,t ,size; size=10;//number of elements to sort for (t=0;t< size; t++) nums[t]=rand( );//loading the array //displaying the array cout<<" original array is : "; for (t=0;t< size; t++) cout<<nums[t]<<" "; cout<<"\n";
//sorting the array for (a=1;a< size ;a++) for (b=size-1;b>=a ;b--)} if(nums[b-1]< nums [b])} //exchange elements t=nums[b-1]; nums[b-1]=nums[b]; nums[b]=t; { {
//displaying sorted array cout<<"Sorted array is: "; for (t=0;t< size; t++) cout<< nums[t]<<" "; getch( ); return 0;{
PART FIVEPART FIVEStringString
3.5 StringsIn C++, a string is defined as a character array that is terminated by a null. A null is specified using ‘\0’ , and is zero. Because of the null terminator, it is necessary to declare a character arrayto be one character longer than the largest string that it would hold. Forexample, if you want to declare an array str that could hold a 10character string, you would write: char str[11] ;Specifying the size as 11 makes room for the null at the end of the string. A string constant is a list of characters enclosed in double quotes. Here are some examples:“ HELLO”“ I like C++ ““#$%@@#$”like this:
“ “ is called a null string. It contains only the null terminator, and no other characters.
Null strings are useful because they represent the empty string.
It is not necessary to manually add the null onto the end of string constants ;
\the C++ compiler does this for you automatically.
Therefore, the string “ HELLO” will appear in memory
H E L L O ‘\0’
3.5.1Reading a string from the keyboardThe easiest way to read a string entered from the keyboard is to make the array that will receive the string the target of cin statement.Example(18)The following program reads a string entered by the user://Using cin to read a string from the keyboard.#include<iostream.h>#include<conio.h>int main( ) } char str[80]; cout<<" Enter a string: "; cin>>str ; //read string from keyboard cout<< "Here is your string : "; cout<<str ; getch( ) ; return 0 ; {
Although this program is technically correct, there still a problem. To see what it is, run the program and try entering the string “ This is a
test “ . As you will see, when the program redisplays your string, it will show
only the word “This”, not the entire sentence. The reason for this is that the C++ I/O system stops reading a string
when the first white space character is encountered. White space characters include spaces, tabs, and new lines.To solve the white space problem, you will need to use another of C++
‘s library functions, gets( ). The general form of a gets( ) call is: gets( array name ) ;The header used by gets( ) is <stdio.h>
Example(19)This version of the preceding program uses gets( ) to allow the entry of the strings containing spaces.
//Using gets( ) to read a string from the keyboard.#include<iostream.h>#include<conio.h>#include<stdio.h>int main( ) } char str[80]; cout<<" Enter a string: "; gets (str) ; //read string from keyboard cout<< "Here is your string : "; cout<<str ; getch( ) ; return 0 ; {
Example(20)Write a program to read a string from the keyboard using cin.
The Program//Using cin to read a string from the keyboard.#include<iostream.h>#include<conio.h>int main( )} char name[80]; cout<<″What is your name? ″; cin>>name; cout<<″ Here is your name :″; cout<<name; getch( ); return 0 ; {
Example(20.1)Write a program to read a string from the keyboard using gets.
The Program//Using gets to read a string from the keyboard.#include<iostream.h>#include<conio.h>#include<stdio.h>int main( ) } char name[80]; cout<<" What is your name? "; gets(name) ; cout<< "Here is your name : "; cout<<name ; getch( ) ; return 0 ; {