sqrt()
sqrt() — Square root.
Built-in function of PHP 8.5. The manual lists it as available in PHP 4, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.
Signature
sqrt(float $num): float
Parameters
| Parameter | Type | What it takes |
|---|---|---|
| $num | float | The argument to process |
Return value
The square root of num or the special value NAN for negative numbers.
Example
A runnable snippet:
// Precision depends on your precision directive echo sqrt(9), PHP_EOL; // 3 echo sqrt(10), PHP_EOL; // 3.16227766 ...
See also
All PHP 8.5 built-in functions
Reference card built from the PHP manual page sqrt() (PHP documentation, CC BY 3.0). The page is generated from the manual, so the wording of the parameter and return value text follows php.net.