Comparison Operators

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 highlights 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.

Basic Usage of Comparison Operators

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";
   }
?>

Output

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

PHP Equality (==) vs Identity (===) Operators

In the below PHP code we will try to compare two variables. One variable is a number and the other variable is text. So it checks if both have the same value (==). Next it checks if both value and type are the same (===).

<?php
   $x = 15;
   $y = "15";

   if ($x == $y) {
  echo "x is equal to y \n";
   }

   if ($x === $y) {
  echo "x is identical to y \n";
   } else {
  echo "x is not identical to y \n";
   }
?>

Output

This will generate the below output −

x is equal to y 
x is not identical to y 

PHP Spaceship Operator

Now the below code is showing the usage of spaceship operator. The spaceship operator returns three possible values – it returns -1 if the first value is smaller, returns 0 if both values are equal and returns 1 if the second value is larger.

<?php
   $a = 5;
   $b = 10;

   echo ($a <=> $b), "\n"; 

   $a = 20;
   echo ($a <=> $b), "\n"; 

   $a = 10;
   echo ($a <=> $b), "\n"; 
?>

Output

This will create the below output −

-1
1
0

Usage of Not Equal (!=) and Not Identical (!==)

In the following example, we are showing the usage of != and !== operators. The != operator checks if both the variables are different and !== checks that both the variables are exactly the same.

<?php
   $p = 50;
   $q = "50";

   if ($p != $q) {
  echo "p is not equal to q \n";
   } else {
  echo "p is equal to q \n";
   }

   if ($p !== $q) {
  echo "p is not identical to q \n";
   } else {
  echo "p is identical to q \n";
   }
?>

Output

Following is the output of the above code −

p is equal to q 
p is not identical to q

PHP Comparison and Logical Operators

In PHP, comparison operators compare two values and logical operators combine multiple conditions. The PHP programbelow shows how to use comparison (>, <) and logical operators (&&, ||) to decide loan eligibility and special discounts.

<?php
   $age = 25;
   $salary = 5000;

   if ($age > 18 && $salary > 3000) {
  echo "Eligible for Loan \n";
   } else {
  echo "Not Eligible for Loan \n";
   }

   if ($age < 30 || $salary < 1000) {
  echo "Special discount applicable \n";
   }
?>

Output

Following is the output of the above code −

Eligible for Loan
Special discount applicable