Check if a number is divisible by another number in PHP

In this tutorial, we are going to learn about how to check if a number is divisible by another number in PHP with the help of examples.

Consider, we have a following number:

$a = 20

To find if a above number 20 is divisible by another number, we should divide the first number by second and get the remainder 0 then only we call it’s a divisible of another number otherwise it is not a divisible.

For example: 20%5 = 0

Using % Modulo operator

To check if a number is divisible by another number, we can use the % modulo operator in PHP.

The modulo % operator returns the remainder of two numbers 20 % 5 = 0, so if we get a remainder 0 then the given number is a divisible of another number otherwise it not a divisible.

Here is an example:

if (20 % 5 == 0) {
  echo "20 is divisible by 5";
}else {
  echo "20 is not divisible by 5";
}

Output:

"20 is divisible by 5"

In the above code we have added 20 % 5 == 0 in if condition. so 20 is divided by 5 and returns the remainder 0 then it prints the output “20 is divisible by 5”.

Example 2 :

if (100 % 10 == 0) {
  echo "100 is divisible by 10";
}else {
  echo "100 is not divisible by 10";
}

Output:

"100 is divisible by 10"

Checking if a number is not divisible by another

To check if a number is not a divisible of another number, we can use the modulo operator % but the remainder of first number by second number is not equal to 0.

Here is an example:

if (25 % 10 != 0){
    echo "25 is not divisible by 10";
}

In the above code, 25 is divided by 10 and returns the remainder 5. So the given number is not divisible of 10.