PHP float

Summary: in this tutorial, you’ll learn about floating-point numbers or floats in PHP.

Introduction to the PHP float #

Floating-point numbers represent numeric values with decimal digits.

Floating-point numbers are often called floats, doubles, or real numbers. Like integers, the range of the floats depends on the platform where PHP runs.

PHP recognizes floating-point numbers in the following common formats:

1.25
3.14
-0.1Code language: PHP (php)

PHP also supports the floating-point numbers in scientific notation:

0.125E1 // 0.125 * 10^1 or 1.25Code language: PHP (php)

Since PHP 7.4, you can use the underscores in floats to make long numbers more readable. For example:

1_234_457.89Code language: PHP (php)

Floating-point number accuracy #

Since the computer cannot represent exact floating-point numbers, it can only use approximate representations.

For example, the result of 0.1 + 0.1 + 0.1 is 0.299999999…, not 0.3. When comparing two floating-point numbers using the == operator, you must be careful.

The following example returns false, which may not be what you expected:

<?php

$total = 0.1 + 0.1 + 0.1;
echo $total == 0.3; // return falseCode language: PHP (php)

Try it

Test a float value #

To check if a value is a floating-point number, you use the is_float() or is_real() function. The is_float() returns true if its argument is a floating-point number; otherwise, it returns false. For example:

<?php

echo is_float(0.5);Code language: PHP (php)

Try it

Output:

1Code language: PHP (php)

Summary #

• Floating-point numbers are numbers with decimal points. Floating-point numbers are also known as floats.
• PHP can only represent floats approximately, not precisely.