Gets n
random elements at unique keys from array
up to the size of array
.
Shuffle the array using the Fisher-Yates algorithm.
Use Array.prototype.slice()
to get the first n
elements.
Omit the second argument, n
to get only one element at random from the array.
代码片段
const sampleSize = ([...arr], n = 1) => {
let m = arr.length;
while (m) {
const i = Math.floor(Math.random() * m--);
[arr[m], arr[i]] = [arr[i], arr[m]];
}
return arr.slice(0, n);
};
使用样例
sampleSize([1, 2, 3], 2); // [3,1]
sampleSize([1, 2, 3], 4); // [2,3,1]