PHP gives automatic data type conversion.

For example, if you provide an integer value to a variable, the type of that variable will automatically be an integer. Next, if you provide a string to the same variable, the type will change to a string.

Integers

It is a number without any decimal part.

Following functions are used to check if the type of a variable is integer:

• is_int()
• is_integer()
• is_long()

Example:

<?php 
	$a = 100;
	$b = -150;
?>

Float

It is a number with a decimal point or a number in the exponential pattern.

Following functions are used to check if the type of a variable is float:

• is_float()
• is_double()

Example:

<?php 
	$a = 21.9;
	$b = -15.351;
?>

NaN

NaN stands for Not a Number.

The following function is used to check if a value is not a number.

• is_nan()