mt_getrandmax

(PHP 4, PHP 5, PHP 7)

mt_getrandmaxShow largest possible random value

Descrierea

mt_getrandmax ( ) : int

Returns the maximum value that can be returned by a call to mt_rand().

Valorile întoarse

Returns the maximum random value returned by a call to mt_rand() without arguments, which is the maximum value that can be used for its max parameter without the result being scaled up (and therefore less random).

Exemple

Example #1 Calculate a random floating-point number

<?php
function randomFloat($min 0$max 1) {
    return 
$min mt_rand() / mt_getrandmax() * ($max $min);
}

var_dump(randomFloat());
var_dump(randomFloat(220));
?>

Exemplul de mai sus va afișa ceva similar cu:

float(0.91601131712832)
float(16.511210331931)

A se vedea și

  • mt_rand() - Generate a random value via the Mersenne Twister Random Number Generator
  • mt_srand() - Seeds the Mersenne Twister Random Number Generator
  • getrandmax() - Show largest possible random value

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User Contributed Notes 1 note

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bishop at php dot net
8 years ago
The upper-bound of this value is platform-independent.  PHP implements the 32-bit version of the Mersenne Twister ("mt"), so the maximum possible value is 2**31 - 1 (2147483647).
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