前端小白突然想到个问题，想请教一下各位 dalao， JavaScript 中的 Math.random()是如何实现随机数的？用了这么久，好像只知其然，而不知其所以然
資深大佬 : damao2250 4
每个浏览器的实现不一样，比如 Chrome V8 的实现：
// ECMA 262 – 15.8.2.14
var rngstate; // Initialized to a Uint32Array during genesis.
function MathRandom() {
var r0 = (MathImul(18030, rngstate[0] & 0xFFFF) + (rngstate[0] >>> 16)) | 0;
rngstate[0] = r0;
var r1 = (MathImul(36969, rngstate[1] & 0xFFFF) + (rngstate[1] >>> 16)) | 0;
rngstate[1] = r1;
var x = ((r0 << 16) + (r1 & 0xFFFF)) | 0;
// Division by 0x100000000 through multiplication by reciprocal.
return (x < 0 ? (x + 0x100000000) : x) * 2.3283064365386962890625e-10;
}
// ECMA 262 – 15.8.2.14
var rngstate; // Initialized to a Uint32Array during genesis.
function MathRandom() {
var r0 = (MathImul(18030, rngstate[0] & 0xFFFF) + (rngstate[0] >>> 16)) | 0;
rngstate[0] = r0;
var r1 = (MathImul(36969, rngstate[1] & 0xFFFF) + (rngstate[1] >>> 16)) | 0;
rngstate[1] = r1;
var x = ((r0 << 16) + (r1 & 0xFFFF)) | 0;
// Division by 0x100000000 through multiplication by reciprocal.
return (x < 0 ? (x + 0x100000000) : x) * 2.3283064365386962890625e-10;
}
https://github.com/v8/v8/blob/dae6dfe08ba9810abbe7eee81f7c58e999ae8525/src/math.js#L144
大佬有話說 (3)