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Operators

PHP Operators

This section lists the different operators used in PHP with some code example:

Operator is a symbol or special character which is used in an expression for manipulation assess or variable and give a result.

Arithmetic Operators is operator that is used to conduct mathematical calculation.

Arithmetic operators:

Operator
Description
Example
Result
+ Addition x=2
x+2 4
- Substraction x=2
5-x 3
* Multiplication x=4
x*5 20
/ Division 15/5
5/2 3
2.5
% Modulus (division remainder) 5%2
10%8
10%2 1
2
0
++ Increment x=5
x++ x=6
-- Decrement x=5
x-- x=4

In the complex expression which is entangled of many operand, operator *, /, and % have the same priority but it is higher rather than operator + and -. For further information, just pay attention to the example as following:

$a = 20 + 4 % 4

4 % 4 will be done first, so that result is 21 not 6.

Pay attention to the example of using arithmetic operator at script as following :

Code:

<html>
 <head>
 <title>Using Arithmetic Operators</title>
 </head>

 <body>
 <?php

print("Addition: ");
 printf("9 + 7 = %d ", 9 + 7);
 printf("9.5 + 7 = %f ", 9.5 + 7);
 printf("9.5 + 7.5 = %f ", 9.5 + 7.5);
 printf("-9.5 + 7.5 = %f ", -9.5 + 7.5);
 print("Reduction: ");
 printf("9 - 7 = %d ", 9 - 7);
 printf("9.5 - 7 = %f ", 9.5 - 7);
 printf("9.5 - 7.5 = %f ", 9.5 - 7.5);
 printf("-9.5 - 7.5 = %f ", -9.5 - 7.5);
 print("Multiplication: ");
 printf("9 * 7 = %d ", 9 * 7);
 printf("9.5 * 7 = %f ", 9.5 * 7);
 printf("9.5 * 7.5 = %f ", 9.5 * 7.5);
 printf("-9.5 * 7.5 = %f ", -9.5 * 7.5);
 print("Division: ");
 printf("9 / 7 = %d ", 9 / 7);
 printf("9.5 / 7 = %f ", 9.5 / 7);
 printf("9.5 / 7.5 = %f ", 9.5 / 7.5);
 printf("-9.5 / 7.5 = %f ", -9.5 / 7.5);
 print("Modulus: ");
 print(" 9 % 7 = "); print(9 % 7 ." ");
 print("9.5 % 7 = "); print(9.5 % 7 ." ");
 print("9.5 % 7.5 = "); print( 9.5 % 7.5." ");
 print("-9.5 % 7.5 = "); print( -9.5 % 7.5." ");
 print("9.5 % -7.5 = "); print( 9.5 % -7.5." ");
 print" ";

?>
 </body>
 </html>

An output of this code will be:

                                                     Addition:
                                                     9 + 7 = 16
                                                     9.5 + 7 = 16.500000
                                                     9.5 + 7.5 = 17.000000
                                                     -9.5 + 7.5 = -2.000000
                                                     Reduction:
                                                     9 - 7 = 2
                                                     9.5 - 7 = 2.500000
                                                     9.5 - 7.5 = 2.000000
                                                     -9.5 - 7.5 = -17.000000
                                                     Multiplication:
                                                     9 * 7 = 63
                                                     9.5 * 7 = 66.500000
                                                     9.5 * 7.5 = 71.250000
                                                     -9.5 * 7.5 = -71.250000
                                                     Division:
                                                     9 / 7 = 1
                                                     9.5 / 7 = 1.357143
                                                     9.5 / 7.5 = 1.266667
                                                     -9.5 / 7.5 = -1.266667
                                                     Modulus:
                                                     9 % 7 = 2
                                                     9.5 % 7 = 2
                                                     9.5 % 7.5 = 2
                                                     -9.5 % 7.5 = -2
                                                     9.5 % -7.5 = 2

Assignment operator (=) is operator where the left operand get value from the right operand. It can also be interpreted as giving operator a value to variable.

Example:

$x = 100; // which mean x is given by value 100.

The assignment process can also be conducted with the right operand which is in the form of expression.

$y = ($x = 100) + 20;

Assignment operator can also be conducted with the combination of aritmatic operator and string operator which enabling you to use the expression and the result becomes its value.

Example:

                                                        $x = 100;
                                                        $x += 90;
                                                        $x = $x + 90;
                                                        $greeting ="good";
                                                        $greeting = "night";       // good night

Pay attention that the assignment can copy the original variable into new variable (assignment by value). PHP have supported assignment by reference. Assignment by reference means that some variable which relates in one of same location (is same variable content)

Its syntax:

$var= &$OtherVariable.

Example:

Code:

<html>
 <head>
 <title>Using Arithmetic Operator</title>
 </head>

 <body>

<?php

$x = "red"; // assignment by reference

$y = &$x; // change $x and $y value

$y = "black"; // remove $x variable from memory

unset ($x); // print $y value ="black"

print ($y);

?>
 </body>
 </html>

An output of this code will be:

black

Assignment operator Table:

Operators Example
Is the same as...
= x=y x=y
+= x+=y x=x+y
-= x-=y x=x-y
*= x*=y x=x*y
/= x/=y x=x/y
.= x.=y x=x.y
%= x%=y x=x%y

Pay attention to the example of using assignment operator at script as following:

Code:

<html>
 <head>
 <title>Using Operators</title>
 </head>

 <body>
 <h1>Operator Assignment</h1>
 <?php
 $x = 15;
 echo ("\$x = $x ");
 $x += 1 ;
 echo ("\$x += 1 = $x ");
 $x = 7;
 echo ("\$x = $x ");
 $x = $x + 2;
 echo ("\$x = \$x + 2 = $x ");
 $x = 87;
 echo ("\$x = $x ");
 $y = &$x;
 echo ("\$y = &\$x = $x ");
 $greeting = "good";
 echo ("\$greeting = $greeting ");
 $greeting .="night";
 echo ("\$greeting .= good = $greeting");
 ?>
 </body>
 </html>

An output of this code will be:

Operator Assignment

                                                     $x = 15
                                                     $x += 1 = 16

                                                     $x = 7
                                                     $x = $x + 2 = 9

                                                     $x = 87
                                                     $y = &$x = 87

                                                     $greeting = good

                                                     $greeting .= good = goodnight

Comparison Operators:

Operator
Description
Example
== is equal to 5==8 returns false
!= is not equal 5!=8 returns true
> is greater than 5>8 returns false
< is less than 5<8 returns true
>= is greater than or equal to 5>=8 returns false
<= is less than or equal to 5<=8 returns true

Logical Operators:

Operator
Description
Example
&& and x=6
y=3
(x < 10 && y > 1) returns true
|| or x=6
y=3
(x==5 || y==5) returns false
! not x=6
y=3
!(x==y) returns true

PHP IF-ELSE STATEMENT

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Basic PHP

Advanced PHP

Example Scripts

PHP Operators

This section lists the different operators used in PHP with some code example:

Assignment operator (=) is operator where the left operand get value from the right operand. It can also be interpreted as giving operator a value to variable.

Example:

Assignment operator Table:

Pay attention to the example of using assignment operator at script as following:

Comparison Operators:

Logical Operators: