PHP: Operators

PHP assignment operator as most of the languages is equal to sign (=). Therefore, we can assign any variable any value using equal sign.

$my_variable = "my world";

$this_variable = 5;

PHP arithmetic operators include:

addition + (example: 2 + 4) , subtraction - (example: 4 -2) ,multiplication *( example: 4 * 3), division / (example: 4/2), modulus % (example 10 % 3).

Modulus gives the remainder after the division is performed. Therefore, 45 %2 would give 1, since, 1 is the remainder left when 45 is divided by 2.

PHP comparison or conditional operators used when if-else (or similar conditional operations) operations are done for checking conditions between variables and values include:

== (equal to), != (not equal to), < (less than), >(greater than), >= (greater than equal to), <= (less than equal to).

We can combine assignment operations for shorthand purposes as follows:

 

<?php

$x = 0;

$y = 0;

$x = $x + 2;

// same as

$y += 2; // $y = 2

$y -= 1; // $y = 1

$y *= 2; // $y = 2

$y /= 2 ; //$y =1

$y %= 1; //$y = 0

$x = 4;

$x++; // is same as $x = $x + 1 or $x += 1; would give 5.

$x-- ; // same as $x = $x -1 or $x-= 1; would give 4.

?>

Also, $x++ known as post-increment and ++x as pre-increment. Similarly, $x-- and --$x are known as post-decrement and pre-decrement.

The difference between post and pre operators is illustrated below:

 

<?php

$x = 5;

echo $x++; // would give 5.

echo $x; // would give 6.

$x = 5;

echo ++$x; // would give 6.

echo $x; // would give 6

?>

 

$x++ would execute after the line has executed and ++x would execute first and then the line in which it is present is executed. Thus, in post-increment ($x++) line is echoed wihout increasing the number and later it was found that the number has increased. In pre-incrment (++$x), the increased number value is reflected in the the line itself where it was applied.

PHP String operators include concatenation that is done by period(.) sign as follows:

 

<?php

$string = "Hello ";

$name = "Bob " ;

$greet =$string.$name." nice meeting you! ";

$greet .= "My pleasure!";

echo $greet;

?>

This would give following output:

Hello Bob nice meeting you! My pleasure!

Note, that string were concatenated using period (.) and later shorthand notation of .= was used that is equivalent to $x = $x .$y.