PHP Operators

Operators -

In all programming languages, operators are used to manipulate or perform operations on variables and values.
There are many operators used in PHP, so we have separated them into the following categories to make it easier to learn them all.
• Assignment Operators
• Arithmetic Operators
• Comparison Operators
• String Operators
• Combination Arithmetic & Assignment Operators



Assignment operator

Assignment operators are used to set a variable equal to a value or set a variable to another variable's value. Such an assignment of value is done with the "=", or equal character. 
Example:
$my_var = 4; 

$another_var = $my_var;
Now both $my_var and $another_var contain the value 4. Assignments can also be used in conjunction with arithmetic operators.

Arithmetic operators

Operator	Name	Description	Example	Result
x+y	Addition	Sum of x and y	2+2	4
x-y	Substraction	Diffrence of x and y	10-4	6
x*y	Multiplication	Product of x and y	12*8	96
x/y	Division	Quotient of x and y	15/5	3
x%y	Modulus	Remainder of x divided by y	20%6	2

Comparison operators

Operator	Name	Descryption	Example
x==y	Equal	True if x is equals to y	5==8 return false
x===y	Identical	True if x is equal to y, and they are of sametype	5==="5" returns false
x != y	Not equal	True if x is not equal to y	5!=8 returns true
x <> y	Not equal	True if x is not equal to y	5<>8 returns true
x !== y	Not identical	True if x is not equal toy, or they are not of same type	5!=="5" returns true
x > y	Greater than	True if x is greater than y	5>8 returns false
x < y Less than	Less than	True if x is less than y	5<8 returns true
x >= y	Greater than or equal to	True if x is greater than or equal to y	5>=8 returns false
x <= y	Less than or  equal to	True if x is less  than or equal to y	5<=8 returns true

String operators

As we have already seen in the Echo Lesson, the period "." is used to add two strings together, or more technically, the period is the concatenation operator for strings.



PHP Code:

$a_string = "Hello";
$another_string = " Billy";
$new_string = $a_string . $another_string;
echo $new_string . "!";

Display:

Hello Billy!


PHP Incrementing/Decrementing Operators




PHP Code:

$x = 4;
echo 'The value of x with post-plusplus = ' . $x++;
echo ' The value of x after the post-plusplus is ' . $x;
$x = 4;
echo '
The value of x with with pre-plusplus = ' . ++$x;
echo ' The value of x after the pre-plusplus is ' . $x;

Display:

The value of x with post-plusplus = 4
The value of x after the post-plusplus is = 5
The value of x with with pre-plusplus = 5
The value of x after the pre-plusplus is = 5 


PHP Logical Operators

Operator	Name	Descryption
x and y	And	True if both x and y
x or y	or	True if either or both x and y
x && y	And	True if both x and y are true
x || y	Or	True if either or both x and y are true
! x	Not	True if x is not true x=6