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lcg_value

(PHP 4, PHP 5, PHP 7, PHP 8)

lcg_valueCombined linear congruential generator

Description

lcg_value(): float

lcg_value() returns a pseudo random number in the range of (0, 1). The function combines two CGs with periods of 2^31 - 85 and 2^31 - 249. The period of this function is equal to the product of both primes.

Caution

This function does not generate cryptographically secure values, and should not be used for cryptographic purposes. If you need a cryptographically secure value, consider using random_int(), random_bytes(), or openssl_random_pseudo_bytes() instead.

Parameters

This function has no parameters.

Return Values

A pseudo random float value between 0.0 and 1.0, inclusive.

• rand() - Generate a random integer
• mt_rand() - Generate a random value via the Mersenne Twister Random Number Generator

User Contributed Notes 3 notes

14
rok kralj gmail com
14 years ago
``` An elegant way to return random float between two numbers:<?phpfunction random_float (\$min,\$max) {   return (\$min+lcg_value()*(abs(\$max-\$min)));}?> ```
15
daniel dot baulig at gmx dot de
11 years ago
``` Choose your weapon:<?phpfunction mt_randf(\$min, \$max){    return \$min + abs(\$max - \$min) * mt_rand(0, mt_getrandmax())/mt_getrandmax(); }function lcg_randf(\$min, \$max){    return \$min + lcg_value() * abs(\$max - \$min);}function randf(\$min, \$max){    return \$min + rand(0,getrandmax()) / getrandmax() * abs(\$max - \$min);}?> ```
-23
Linndows
5 years ago
``` I think best example...<?php\$x=0;while(\$x<=5){\$x++;echo lcg_value()+\$x."\n";   }     echo lcg_value()+\$x-(2*lcg_value()); echo "\n";?> ```