如何从数组中删除 n 而不对其进行变异？

Question

你好这个问题需要删除

Answer 1

您可以使用filteror reduce，或者先使用 using 复制数组slice，然后执行splice。

就个人而言，我喜欢filter它的简单性和明确的意图

筛选

function removeItem(array, n) {
  return array.filter((elem, i) => i !== n);
}

const original = [1,2,3,4];

console.log(removeItem(original, 1));
console.log(original);

降低

function removeItem (array, n) {
  return array.reduce((result, elem, i) => {
    if (i !== n) result.push(elem);
    return result;
  }, [])
}

const original = [1,2,3,4];

console.log(removeItem(original, 1));
console.log(original);

切片和拼接

function removeItem(array, n) {
  const result = array.slice();
  result.splice(n, 1);
  return result;
}

const original = [1,2,3,4];

console.log(removeItem(original, 1));
console.log(original);

性能测试

https://jsperf.com/so53833297

文档

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice