ASSIGNMENT : C++ PROGRAMMING

QUESTIONS

1. WHO IS WRITTEN C++

Bjarne Stroustrup, a Danish computer scientist, began his work on C++'s predecessor "C with Classes" in

1979. The motivation for creating a new language originated from Stroustrup's experience in programming for his

Ph.D. thesis. Stroustrup found that Simula had features that were very helpful for large software development,

but the language was too slow for practical use, while BCPL was fast but too low-level to be suitable for large

software development. When Stroustrup started working in AT&T Bell Labs, he had the problem of analyzing

the UNIX kernel with respect to distributed computing. Remembering his Ph.D. experience, Stroustrup set out to

enhance the C language with Simula-like features.] C was chosen because it was general-purpose, fast, portable

and widely used. As well as C and Simula's influences, other languages also influenced C++, including ALGOL

68, Ada, CLU and ML.

Initially, the class, derived class, strong typing, inlining and default argument features were added to C via

Stroustrup's "C with Classes" to C compiler, Cpre.

In 1983, it was renamed from C with Classes to C++ ("++" being the increment operater in C). New features were

added including virtual functions, function name and operator overloading, references, constants, type-safe free-

store memory allocation (new/delete), improved type checking, and BCPL style single-line comments with two

forward slashes , as well as the development of a proper compiler for C++, Cfront.

In 1985, the first edition of The C++ Programming Language was released, which became the definitive

reference for the language, as there was not yet an official standard.The first commercial implementation of C++

was released in October of the same year.

In 1989, C++ 2.0 was released, followed by the updated second edition of The C++ Programming Language in

1991.New features in 2.0 included multiple inheritance, abstract classes, static member functions, const member

functions, and protected members. In 1990, The Annotated C++ Reference Manual was published. This work

became the basis for the future standard. Later feature additions included templates, exceptions, namespaces,

new casts, and a boolean type.

After the 2.0 update, C++ evolved relatively slowly. In 2011, the C++11 standard was released, adding numerous

new features, enlarging the standard library further, and providing more facilities to C++ programmers. After a

minor C++14 update, released in December 2014, various new additions are planned for 2017.

2. STATE STATEMENTS BELOW AND GIVE AN EXAMPLE APPLICATION IN C++ PROGRAM.a) GO TO

/* C++ program to demonstrate the working of goto statement. *//* This program calculates the average of numbers entered by user. *//* If user enters negative number, it ignores that number and calculates the average of number entered before it.*/

# include <iostream>using namespace std;int main() { float num, average, sum = 0.0; int i, n; cout<<"Maximum number of inputs: "; cin>>n;

for(i=1; i <= n; ++i) { cout<<"Enter n"<<i<<": "; cin>>num; if(num < 0.0) { goto jump; /* Control of the program moves to jump; */ } sum += num; } jump: average=sum/(i-1); cout<<"\nAverage = "<<average; return 0;}

b) WHILE

The while construct consists of a block of code and a condition / expression . The condition/expression is evaluated, and if the condition/expression is true , the code within the block is executed. This repeats until the condition/expression becomes false. Because the while loop checks the condition/expression before the block is executed, the control structure is often also known as a pre-test loop. Compare this with the do while loop, which tests the condition/expression after the loop has executed.

while (true) { //do complicated stuff if (someCondition) break; //more stuff}

c) BREAK AND CONTINUE

In C programming, break is used in terminating the loop immediately after it is encountered. The break statement is used with conditional if statement.

/* C program to demonstrate the working of break statement by terminating a loop, if user inputs negative number*/# include <stdio.h>int main(){ float num,average,sum; int i,n; printf("Maximum no. of inputs\n"); scanf("%d",&n); for(i=1;i<=n;++i){ printf("Enter n%d: ",i); scanf("%f",&num); if(num<0.0) break; //for loop breaks if num<0.0 sum=sum+num;} average=sum/(i-1); printf("Average=%.2f",average); return 0;}

It is sometimes desirable to skip some statements inside the loop. In such cases, continue statements are used.

//program to demonstrate the working of continue statement in C programming # include <stdio.h>int main(){ int i,num,product; for(i=1,product=1;i<=4;++i){ printf("Enter num%d:",i); scanf("%d",&num); if(num==0) continue; / *In this program, when num equals to zero, it skips the statement product*=num and continue the loop. */ product*=num;} printf("product=%d",product);return 0;}

d) WHILE TRUEI'm curious about using a while statement with a true condition. What is the advantage of using a while(true) statement with break to exit the while statement over something like a for loop? I guess I'm just curious when a good time to use this technique would be? I saw it demonstrated in a quick sort algorithm at school today and was just curious about it.

#include <iostream>using namespace std;

int main (int argc, char * const argv[]) {

int counter = 9;

while (true) {

cout << "Counter: " << counter << endl;;counter--;

if (counter == 0) {break;

}

}

return 0;}

e) DO/WHILE

The do-while statement can also terminate when a break, goto, or return statement is executed within the statement body.

#include <iostream>

 int main(){    // selection must be declared outside do/while loop    int selection;     do    {        std::cout << "Please make a selection: \n";        std::cout << "1) Addition\n";        std::cout << "2) Subtraction\n";        std::cout << "3) Multiplication\n";        std::cout << "4) Division\n";        std::cin >> selection;    }    while (selection != 1 && selection != 2 &&        selection != 3 && selection != 4);     // do something with selection here    // such as a switch statement     std::cout << "You selected option #" << selection << "\n";     return 0;}

f) JUMP/LOOPThe Loop jump is a figure skating jump that takes off from a back outside edge and lands on the same backwards outside edge. For a jump with counterclockwise rotation, this is the right back outside edge. It is named from its similarity to the loop compulsory figure. The invention is widely credited to Werner Rittberger, and the jump is also known as the "Rittberger" in Europe. However, evidence exists that it may have been first done as early as the 1880s.

g) IF/ELSE

An if statement can be followed by an optional else statement, which executes when the boolean expression is false.

if(condition){ // Block For Condition Success}else{  // Block For Condition Fail}

#include <iostream>

using namespace std;

int main ()

{

// local variable declaration:

int a = 100;

// check the boolean condition

if( a < 20 )

{

// if condition is true then print the following

cout << "a is less than 20;" << endl;

}

else

{

// if condition is false then print the following

cout << "a is not less than 20;" << endl;

}

cout << "value of a is : " << a << endl;

return 0;

}