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# srand

(PHP 3, PHP 4, PHP 5)

srand -- Seed the random number generator

## Description

void srand ( [int seed] )

Seeds the random number generator with seed. Since PHP 4.2.0, the seed becomes optional and defaults to a random value if omitted.

Example 1. srand() example
`<?php // seed with microseconds function make_seed() { list($usec, $sec) = explode(' ', microtime()); return (float) $sec + ((float) $usec * 100000); } srand(make_seed()); $randval = rand(); ?>`

> Note: As of PHP 4.2.0, there is no need to seed the random number generator with srand() or mt_srand() as this is now done automatically.

See also: rand(), getrandmax(), and mt_srand().

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