In PHP, Comparison operators are used to compare two values and determine their relationship. These operators return a Boolean value, either True or False, based on the result of the comparison.
The following table highligts the comparison operators that are supported by PHP. Assume variable $a holds 10 and variable $b holds 20, then −
| Operator | Description | Example |
|---|---|---|
| == | Checks if the value of two operands are equal or not, if yes then condition becomes true. | ($a == $b) is not true |
| != | Checks if the value of two operands are equal or not, if values are not equal then condition becomes true. | ($a != $b) is true |
| > | Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true. | ($a > $b) is false |
| < | Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true. | ($a < $b) is true |
| >= | Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true. | ($a >= $b) is false |
| <= | Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true. | ($a <= $b) is true |
Additionally, these operators can also be combined with logical operators (&&, ||, !) to form complex conditions for decision making in PHP programs.
Example
The following example shows how you can use these comparison operators in PHP −
<?php
$a = 42;
$b = 20;
if ($a == $b) {
echo "TEST1 : a is equal to b n";
} else {
echo "TEST1 : a is not equal to b n";
}
if ($a > $b) {
echo "TEST2 : a is greater than b n";
} else {
echo "TEST2 : a is not greater than b n";
}
if ($a < $b) {
echo "TEST3 : a is less than b n";
} else {
echo "TEST3 : a is not less than b n";
}
if ($a != $b) {
echo "TEST4 : a is not equal to b n";
} else {
echo "TEST4 : a is equal to b n";
}
if ($a >= $b) {
echo "TEST5 : a is either greater than or equal to b n";
} else {
echo "TEST5 : a is neither greater than nor equal to b n";
}
if ($a <= $b) {
echo "TEST6 : a is either less than or equal to b n";
} else {
echo "TEST6 : a is neither less than nor equal to b";
}
?>
It will produce the following output −
TEST1 : a is not equal to b TEST2 : a is greater than b TEST3 : a is not less than b TEST4 : a is not equal to b TEST5 : a is either greater than or equal to b TEST6 : a is neither less than nor equal to b