I need a PHP function that generate random number identical to javascript Math.random()
width the same seed.
MDN about math.random():
The random number generator is seeded from the current time, as in
Java.
As far I tried the PHP's rand() generates something like that:
srand( time() ); // I use time as seed, like javascript does
echo rand();
Output: 827382
And javascript seems to generate random numbers on it's own way:
Math.random(); Output: 0.802392144203139
I need PHP code that is equivalent for math.random(), not new javascript code. I can't change javascript.
You could use a function that returns the value:
PHP
function random() {
return (float)rand()/(float)getrandmax();
}
// Generates
// 0.85552537614063
// 0.23554185613575
// 0.025269325846126
// 0.016418958098086
JavaScript
var random = function () {
return Math.random();
};
// Generates
// 0.6855146484449506
// 0.910828611580655
// 0.46277225855737925
// 0.6367355801630765
@elclanrs solution is easier and doesn't need the cast in return.
Update
There's a good question about the difference between PHP mt_rand()
and rand()
here:
What's the disadvantage of mt_rand?
Javascript's Math.random gives a random number between 0 and 1. Zero is a correct output, but 1 should not be included. @thiagobraga's answer could give 1 as an output. My solution is this:
function random(){
return mt_rand() / (mt_getrandmax() + 1);
}
This will give a random number between 0 and 0.99999999953434.
You could try:
function random () {
return (float)("0." . rand(1e15, 999999999999999));
}
Or even:
function random () {
return rand(1e15, 999999999999999) / 1e15;
}
However, @elclanrs solution seems a lot easier. I tried.