Perl version
Manual
Reference
Modules
Please note: Many features of this site require JavaScript. You appear to have JavaScript disabled, or are running a non-JavaScript capable web browser.
To get the best experience, please enable JavaScript or download a modern web browser such as Internet Explorer 8, Firefox, Safari, or Google Chrome.
Return the positive square root of EXPR. If EXPR is omitted, uses $_ . Works only for non-negative operands unless you've loaded the Math::Complex module.
use Math::Complex; print sqrt(-4); # prints 2i