Advanced php

Advanced PHP

PHP Operators Control Structures PHP Functions Arrays

*Property of STI K0032

OPERATOR is something that you feed with one or more values

characters or set of characters that perform a special operation within the PHP code


ARITHMETIC OPERATORSused to perform simple mathematical operations such as addition, subtraction, multiplication, division, etc

Example Name Result$a + $b Addition (+) Sum of $a and $b$a - $b Subtraction (-) Difference of $a

and $b$a * $b Multiplication

(*)Product of $a and $b

$a / $b Division (/) Quotient of $a and $b

$a % $b Modulus (%) Remainder of $a divided by $b

$a**$b Exponentiation (**)

Result of raising $a to the $b‘th power (PHP 5)


ASSIGNMENT OPERATORSused to transfer values to a variable

Operator

Assignment Same as Description

= a=b a = b

The left operand gets the value of the expression on the right

+= a+=b a = a + b Addition-= a-=b a = a – b Subtraction*= a*=b a = a * b Multiplication/= a/=b a = a / b Division%= a%=b a = a % b Modulus


COMPARISON OPERATORSallow you to compare two values

Example Name Result$a = = $b Equal TRUE if $a is equal to $b.$a = = = $b

Identical TRUE if $a is equal to $b, and they are of the same type. (PHP 4 only)

$a != $b Not equal TRUE if $a is not equal to $b.$a <> $b Not equal TRUE if $a is not equal to $b.$a != = $b

Not identical TRUE if $a is not equal to $b, or they are not of the same type. (PHP 4 only)

$a < $b Less than TRUE if $a is strictly less than $b.$a > $b Greater than TRUE if $a is strictly greater than

$b.

$a <= $b Less than or equal

TRUE if $a is less than or equal to $b.

$a >= $b Greater than or equal

TRUE if $a is greater than or equal to $b.


INCREMENT/DECREMENT OPERATORS

increment operators are used to increase the value of a variable by 1

decrement operators are used to decrease the value of a variable by 1

Example

Name Effect

++$a Pre-increment Increment $a by one. Then returns $a.

$a++ Post-increment Returns $a, then increments $a by one.

--$a Pre-decrement Decrements $a by one, then returns $a.

$a-- Post-decrement Returns $a, then decrements $a by one.


INCREMENT/DECREMENT OPERATORS

Sample script<?phpecho "<h3>Postincrement</h3>";$a = 5;echo "Should be 5: " . $a++ . "<br />\n";echo "Should be 6: " . $a . "<br />\n";

echo "<h3>Preincrement</h3>";$a = 5;echo "Should be 6: " . ++$a . "<br />\n";echo "Should be 6: " . $a . "<br />\n";?


LOGICAL OPERATORSused to combine conditional statements

Example Name Result$a and $b AND TRUE if both $a and $b are

TRUE.$a or $b OR TRUE if either $a or $b is TRUE.$a xor $b XOR TRUE if either $a or $b is TRUE,

but not both.! $a NOT TRUE if $a is not TRUE.$a && $b AND TRUE if both $a and $b are

TRUE.$a | | $b OR TRUE if either $a or $b is TRUE.


STRING OPERATORS two string operators

concatenation operator (.) - returns the concatenation of its right and left arguments

concatenation assignment operator (.=) - appends the argument on the right side to the argument on the left side<?php$a = "Hello ";$b = $a . "World!"; // now $b contains "Hello World!" $a = "Hello ";$a .= "World!"; // now $a contains "Hello World!"?>


PHP ARRAY OPERATORSPHP array operators are used to compare arraysExample Name Result

$a + $b Union (+) Union of $a and $b$a = = $b Equality (==) Returns true of $a and $b have

the same value$a === $b Identity (===) Returns true if $a and $b have

the same value, same order, and of the same type

$a != $b Inequality (!=) Returns true if $a is not equal to $b

$a <> $b Inequality (<>) Returns true if $a is not equal to $b

$a !== $b Not-Identity (!==)

Returns true if $a is not identical to $b


CONTROL STRUCTURES: IF STATEMENT

The if statement is one of the most important features of many languages

It allows conditional execution of code fragments

Use PHP if statement when you want your program to execute a block of code only if a specified condition is true


IF STATEMENTSyntax:

Example:

If (condition) {statement to be executed if condition is true;}

<?php$t = date("H");if ($t < "12") { echo "Good morning!";}?>


IF…ELSE STATEMENT This control structure execute some code if a condition is met and do something else if the condition is not met

Else extends an if statement to execute a statement in case the condition in the if statement evaluates to false

Syntax:If (condition) {statement to be executed if condition

is true;} else {

Statement to be executed if condition is false;}


IF…ELSE STATEMENTExample:

The else statement is only executed if the condition in the if statement is evaluated to false, and if there were any elseif expressions – only if they evaluated to false as well

<?php$t = date("H");if ($t < "12") { echo "Good morning!";} else {

echo “Good afternoon!”;}?>


ELSEIF STATEMENTa combination of if and else it extends an if statement to execute a different statement in case the original if expression evaluates to FALSE

Syntax:If (condition) {

statement to be executed if condition is true;} elseif (condition) {

Statement to be executed if condition is true;} else {

Statement to be executed if condition is false;}


ELSEIF STATEMENTExample:<?php$t = date("H");

if ($t < "12") { echo "Good morning!";} elseif ($t < "18") { echo "Good afternoon!";} else { echo "Have a good evening!";}?>


SWITCH STATEMENT similar to a series of if statements on the same expression

Syntax:switch (n) {case 1:

Statement to be executed if n=case 1;Break;

case 2:Statement to be executed if n=case 2;Break;

case 3:Statement to be executed if n=case 3;Break;

...Default:Statement to be executed if n is not equal to all

cases;}


SWITCH STATEMENTExample:

<?php$fruit = "mango";switch ($fruit) { case "apple":

echo "My favorite fruit is apple!"; break; case "banana":

echo " My favorite fruit is banana!"; break; case "mango":

echo " My favorite fruit is mango!"; break; default:

echo "My favorite fruit is not in the list!";}?>


WHILE STATEMENTWhile loops are the simplest type of loop in PHP. They behave like their C counterparts

The basic form of a while statement isWhile (condition is true) {

Statement to be executed here...;}


WHILE STATEMENTExample:

<?php$a = 1;While ($a <=10) {

echo “The number is: $a <br>”;$a++;

}?>


DO…WHILE STATEMENTdo...while loops are very similar to while loops, except the truth expression is checked at the end of each iteration instead of in the beginning

do…while statement will always execute the blocked of code once, it will then checked the condition, and repeat the loop while the condition is true


DO…WHILE STATEMENTSyntax:

Example:

Do {Statement to be executed;

} while (condition is true);

<?php$a = 1;Do {

echo “The number is: $a <br>”;$a++; }While ($a <=10);?>


FOR STATEMENTexecutes block of codes in a specified number of times

basically used when you know the number of times the code loop should run

Syntax:for (initialization; condition; increment) {

statement to be executed}


FOR STATEMENT

Initialization: It is mostly used to set counter

Condition: It is evaluated for each loop iteration

Increment: Mostly used to increment a counter


FOR STATEMENTExample:

Result:

<?php for ($a = 1; $a <= 5; $a++) { echo "The number is: $a <br>";} ?>


FUNCTIONself-contained blocked of codes that perform a specified “function” or task

executed by a call to the functioncan be called anywhere within a pageoften accepts one or more parameters (“also referred to as arguments”) which you can pass to it


FUNCTIONSyntax:

The declaration of a user defined function starts with the word “function” followed by a short but descriptive name for that function

function functionName(){

Statement to be executed;}


FUNCTIONExample:

Result:

<?phpfunction callMyName() { echo "Francesca Custodio"; }callMyName();?>


FUNCTION ARGUMENTSFunction arguments are just like variables specified right after the function name inside the parentheses

Example:<?phpfunction MyFamName($Fname){echo "$Fname Garcia. <br>”; }MyFamName("Allen");MyFamName("Patrick");MyFamName("Hannah");?>


FUNCTION RETURNS A VALUEFunction returns a value using the return statement

Example:<?phpfunction sum($a, $b) { $ab = $a + $b; return $ab;}echo "5 + 10 = " . sum(5, 10) . "<br>";echo "7 + 13 = " . sum(7, 13) . "<br>";echo "2 + 4 = " . sum(2, 4);?>


Having 3 car names (Honda, Mazda, and Mitsubishi), how will you store these car names in a variable?

Answer:$car1 = “Honda”;$car2 = “Mazda”;$car3 = “Mitsubishi”;

However, what if you want to loop through the cars and look for a specific one? And what if you had hundreds or thousands of cars? What will you do?

Answer:Create an array and store them to a single

variable.


ARRAYSPHP array is a special variable which allows you to store multiple values in a single variable$cars = array(“Honda”, “Mazda”, “Mitsubishi”);


ARRAYSThe values of an array can be accessed by referring to its index number

Result:

<?php$cars = array("Honda", "Mazda", "Mitsubishi"); echo "I have " . $cars[0] . ", " . $cars[1] “,” . ", and " . $cars[2] . ".";?>


TYPES OF PHP ARRAYSThree (3) different types of PHP arrays

Indexed arrayAssociative arrayMultidimensional array


INDEXED ARRAYSIndexed arrays or numeric arrays use number as key

The key is the unique identifier, or id of each item within an array

index number starts at zero


INDEXED ARRAYSTwo ways to create an array:

1. Automatic key assignment

2. Manual key assignment

$Fruits = array(“Mango”, ”Santol”, ”Apple”, “Banana”);

$fruit[0] = “Mango”;$fruit[1] = “Santol”;$fruit[2] = “Apple”;$fruit[3] = “Banana”;


ARRAY COUNT() FUNCTIONThe count() function is used to return the length (the number of elements) of an arrayExample:

Result:

$fruit = array(“Mango”, ”Santol”, ”Apple”, “Banana”);$arrlength=count($fruit);echo $arrlength;


ARRAY: DISPLAYING SPECIFIC CONTENT

Example:

Result:

$Fruit = array(“Mango”, ”Santol”, ”Apple”, “Banana”);echo $fruit[1];


LOOPING THROUGH INDEXED ARRAY

Loop construct is used to loop through and print all the values of a numeric array

For loop structure is best to use in numeric array<?php$fruit = array("Mango", "Santol", "Apple", "Banana");

$arrlength = count($fruit);for ($i = 0; $i < $arrlength; $i++){

echo $fruit[$i];echo "<br>";

}?>


ASSOCIATIVE ARRAYSarrays that use named keys as you assigned to them

Associative arrays are similar to numeric arrays but instead of using a number for the key

it use a value. Then assign another value to the key


ASSOCIATIVE ARRAYSTwo options to create an associative array1. First:

2. Second:

$fruit = array (“Mango”=>”100”, “Santol”=>”200”, “Apple”=>”300”);

$fruit [‘Mango’] = “100”;$fruit [‘Santol’] = “200”;$fruit [‘Apple’] = “300”;


DISPLAYING THE CONTENT OF AN ASSOCIATIVE ARRAY

Displaying the content of an associative array is compared with numeric or indexed array, by referring to its key

Example:

Output:

<?php$fruit = array("Mango" => "100 per kilo", "Santol" => "200 per kilo", "Apple" => "300 per kilo");

echo "Santol:" . $fruit["Santol"];?>


LOOPING THROUGH AN ASSOCIATIVE ARRAY

Loop construct is used to loop through and print all the values of an associative array

For each loop structure is best to use in associative array

Example:<?php$fruit = array("Mango", "Santol", "Apple", "Banana");$arrlength = count($fruit);foreach($fruit as $x => $x_value) {

echo "Key = " . $x . ", Value = " . $x_value;echo "<br>";

}?>


MULTIDIMENSIONAL ARRAYSan array that contains another array as a value, which in turn can hold another array as well

This can be done as many times as can be wish – could have an array inside another array, which is inside another array, etc

In such a way, it is possible to create two- or three-dimensional arrays


MULTIDIMENSIONAL ARRAYSName QTY Sold

Mango 100 96Apple 60 59Santol 110 100<?php$fruit = array ( array("Mango",100,96), array("Apple",60,59), array("Santol",110,100) );?>


MULTIDIMENSIONAL ARRAYS The two-dimensional array name $fruit array which has two indices: row and column - contains three arrays. To get access to each specific element of the $fruit array, one must point to the two indices.

Example:

Result:

echo $fruit[0][0].": QTY: ".$fruit[0][1].", sold: ".$fruit[0][2].".<br>";echo $fruit[1][0].": QTY: ".$fruit[1][1].", sold: ".$fruit[1][2].".<br>";echo $fruit[2][0].": QTY: ".$fruit[2][1].", sold: ".$fruit[2][2].".<br>";


MULTIDIMENSIONAL ARRAYS Using for loop statement to get the element of the $fruit array

Result:

for ($row = 0; $row < 3; $row++) { echo "<p><b>Row number $row</b></p>"; echo "<ul>"; for ($col = 0; $col < 3; $col++) { echo "<li>".$fruit[$row][$col]."</li>"; } echo "</ul>";}

Advanced php

Internet

Transcript of Advanced php