使用javascript不重复的数组中的随机项？

Question

如何从不重复的数组中获取随机项？

我有一个元素数组，比如

var a = ["Mango", "Orange", "Banana", "Apple", "Grapes", "Berry", "Peach"]

我想从数组a中随机获取3个项目

var random = ["Banana", "Berry", "Peach"]

Answer 1

var a = ["Mango","Orange","Banana","Apple","Grapes","Berry","Peach"];

function searchRandom(count, arr){
  let answer = [], counter = 0;
 
  while(counter < count){
    let rand = arr[Math.floor(Math.random() * arr.length)];
    if(!answer.some(an => an === rand)){
      answer.push(rand);
      counter++;
    }
  }
  
  return answer;
}

console.log(searchRandom(3,a))

灵活地支持您想要的任何count 并确保唯一性

Answer 2

var a = ["Mango","Orange","Banana","Apple","Grapes","Berry","Peach"]
var res = a.sort(function() {
  return 0.5 - Math.random();
});
console.log(res.slice(a,3))

Answer 3

这应该没有任何重复：

const a = ["Mango","Orange","Banana","Apple","Grapes","Berry","Peach"]
const b = a.slice()
const newArr = [];

for(let i= 0; i<3; i++){
 let arr = b[Math.floor(Math.random()*b.length)];
  
 let index = b.indexOf(arr);
  
  b.splice(index, 1 );
  
  newArr.push(arr)
  
}

console.log(newArr)

Answer 4

试试这个：-

var a = ["Mango","Orange","Banana","Apple","Grapes","Berry","Peach"]
b = _.shuffle(a).slice(0,5);
console.log(b);

Answer 5

我想改进 Willem van der Veen 的答案，因为他的代码可能返回未定义。这是因为arrayClone取出了随机项但随机数仍在前一个索引长度的范围内。因此，解决方案是我们也必须减少 arrayClone 的长度：

    const array = [0, 1 ,2 ,3 ,4, 5, 6, 7, 8 , 9]

    const arrayClone = array.slice()

    let arrayLength = array.length

    let newArray = []

    for (  let i = 0; i < 5; i++) {
        let arr = arrayClone[Math.floor(Math.random() * arrayLength)]

        arrayLength--

        let index = arrayClone.indexOf(arr)

        arrayClone.splice(index, 1)

        newArray.push(arr)
     }


      console.log(newArray)