What is Operator?
Simple answer can be
given using expression 4 + 5 is equal to 9. Here 4 and 5 are called operands
and + is called operator. PHP language supports following type of operators.
- Arithmetic Operators
- Comparision Operators
- Logical (or Relational) Operators
- Assignment Operators
- String Operators
Airthmatic Operators:
|
Operator
|
Description
|
Example
|
|
+
|
Adds two operands
|
A + B will give 30
|
|
-
|
Subtracts second operand from the first
|
A - B will give -10
|
|
*
|
Multiply both operands
|
A * B will give 200
|
|
/
|
Divide numerator by denumerator
|
B / A will give 2
|
|
%
|
Modulus Operator and remainder of after an integer division
|
B % A will give 0
|
|
++
|
Increment operator, increases integer value by one
|
A++ will give 11
|
|
--
|
Decrement operator, decreases integer value by one
|
A-- will give 9
|
Examples:
<?php
$x=10;
$y=6;
echo ($x + $y); //
outputs 16
echo ($x - $y); //
outputs 4
echo ($x * $y); //
outputs 60
echo ($x / $y); //
outputs 1.6666666666667
echo ($x % $y); //
outputs 4
?>
Comparison Operators:
|
Operator
|
Name
|
Example
|
Result
|
|
==
|
Equal
|
$x == $y
|
True if $x is equal to $y
|
|
===
|
Identical
|
$x === $y
|
True if $x is equal to $y, and they are of the same type
|
|
!=
|
Not equal
|
$x != $y
|
True if $x is not equal to $y
|
|
<>
|
Not equal
|
$x <> $y
|
True if $x is not equal to $y
|
|
!==
|
Not identical
|
$x !== $y
|
True if $x is not equal to $y, or they are not of the same
type
|
|
>
|
Greater than
|
$x > $y
|
True if $x is greater than $y
|
|
<
|
Less than
|
$x < $y
|
True if $x is less than $y
|
|
>=
|
Greater than or equal to
|
$x >= $y
|
True if $x is greater than or equal to $y
|
|
<=
|
Less than or equal to
|
$x <= $y
|
True if $x is less than or equal to $y
|
Example:
<?php
$x=100;
$y="100";
var_dump($x == $y);
echo
"<br>";
var_dump($x === $y);
echo
"<br>";
var_dump($x != $y);
echo
"<br>";
var_dump($x !== $y);
echo
"<br>";
$a=50;
$b=90;
var_dump($a > $b);
echo
"<br>";
var_dump($a < $b);
?>
PHP
Assignment Operators
The PHP assignment operators is used to write a value to a
variable.
The basic assignment operator in PHP is "=". It means
that the left operand gets set to the value of the assignment expression on the
right.
|
Assignment
|
Same as...
|
Description
|
|
x = y
|
x = y
|
The left operand gets set to the value of the expression on
the right
|
|
x += y
|
x = x + y
|
Addition
|
|
x -= y
|
x = x - y
|
Subtraction
|
|
x *= y
|
x = x * y
|
Multiplication
|
|
x /= y
|
x = x / y
|
Division
|
|
x %= y
|
x = x % y
|
Modulus
|
Examples:
x = y
x = y
The left operand gets
set to the value of the expression on the right
x += y
x = x + y
Addition
x -= y
x = x - y
Subtraction
x *= y
x = x * y
Multiplication
x /= y
x = x / y
Division
x %= y
x = x % y
Modulus
Examples:
<?php
$x=10;
echo $x; // outputs 10
$y=20;
$y += 100;
echo $y; // outputs 120
$z=50;
$z -= 25;
echo $z; // outputs 25
$i=5;
$i *= 6;
echo $i; // outputs 30
$j=10;
$j /= 5;
echo $j; // outputs 2
$k=15;
$k %= 4;
echo $k; // outputs 3
?>
PHP
String Operators
|
Operator
|
Name
|
Example
|
Result
|
|
.
|
Concatenation
|
$txt1 = "Hello"
$txt2 = $txt1 . " world!"
|
Now $txt2 contains "Hello world!"
|
|
.=
|
Concatenation assignment
|
$txt1 = "Hello"
$txt1 .= " world!"
|
Now $txt1 contains "Hello world!"
|
Example:
<?php
$a = "Hello";
$b = $a . "
world!";
echo $b; // outputs
Hello world!
$x="Hello";
$x .= "
world!";
echo $x; // outputs
Hello world!
?>
PHP
Logical Operators
|
Operator
|
Name
|
Example
|
Result
|
|
and
|
And
|
$x and $y
|
True if both $x and $y are true
|
|
or
|
Or
|
$x or $y
|
True if either $x or $y is true
|
|
xor
|
Xor
|
$x xor $y
|
True if either $x or $y is true, but not both
|
|
&&
|
And
|
$x && $y
|
True if both $x and $y are true
|
|
||
|
Or
|
$x || $y
|
True if either $x or $y is true
|
|
!
|
Not
|
!$x
|
True if $x is not true
|
Examples:
<?php
$a = 42;
$b = 0;
if( $a
&& $b ){
echo "TEST1 : Both a and b are true<br/>";
}else{
echo "TEST1 : Either a or b is false<br/>";
}
if( $a and
$b ){
echo "TEST2 : Both a and b are true<br/>";
}else{
echo "TEST2 : Either a or b is false<br/>";
}
if( $a ||
$b ){
echo "TEST3 : Either a or b is true<br/>";
}else{
echo "TEST3 : Both a and b are false<br/>";
}
if( $a or
$b ){
echo "TEST4 : Either a or b is true<br/>";
}else{
echo "TEST4 : Both a and b are false<br/>";
}
$a = 10;
$b = 20;
if( $a ){
echo "TEST5 : a is true <br/>";
}else{
echo "TEST5 : a is false<br/>";
}
if( $b ){
echo "TEST6 : b is true <br/>";
}else{
echo "TEST6 : b is false<br/>";
}
if( !$a ){
echo "TEST7 : a is true <br/>";
}else{
echo "TEST7 : a is false<br/>";
}
if( !$b ){
echo "TEST8 : b is true <br/>";
}else{
echo "TEST8 : b is false<br/>";
}
?>
PHP Array
Operators
The PHP array operators are used to compare arrays:
|
Operator
|
Name
|
Example
|
Result
|
|
+
|
Union
|
$x + $y
|
Union of $x and $y (but duplicate keys are not overwritten)
|
|
==
|
Equality
|
$x == $y
|
True if $x and $y have the same key/value pairs
|
|
===
|
Identity
|
$x === $y
|
True if $x and $y have the same key/value pairs in the same
order and of the same types
|
|
!=
|
Inequality
|
$x != $y
|
True if $x is not equal to $y
|
|
<>
|
Inequality
|
$x <> $y
|
True if $x is not equal to $y
|
|
!==
|
Non-identity
|
$x !== $y
|
True if $x is not identical to $y
|
Example:
<?php
$x = array("a"
=> "red", "b" => "green");
$y = array("c"
=> "blue", "d" => "yellow");
$z = $x + $y; // union
of $x and $y
var_dump($z);
var_dump($x == $y);
var_dump($x === $y);
var_dump($x != $y);
var_dump($x <>
$y);
var_dump($x !== $y);
?>
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