js indexof 多值

let arr = [1, 2, 3, 4, 5];

// 查找值为 3 的元素的索引
let index = arr.indexOf(3);
console.log(index); // 输出：2

// 查找不存在的元素的索引
index = arr.indexOf(6);
console.log(index); // 输出：-1

function findIndexes(arr, values) {
  let indexes = [];
  for (let value of values) {
    let index = arr.indexOf(value);
    if (index !== -1) {
      indexes.push(index);
    }
  }
  return indexes;
}

let arr = [1, 2, 3, 4, 5, 3];
let valuesToFind = [3, 6];
let indexes = findIndexes(arr, valuesToFind);
console.log(indexes); // 输出：[2, 5]

let arr = [1, 2, 3, 4, 5, 3];
let valuesToFind = [3, 6];
let indexes = valuesToFind.filter(value => arr.includes(value)).map(value => arr.indexOf(value));
console.log(indexes); // 输出：[2, 5]

let arr = [1, 2, 3, 4, 5, 3];
let valuesToFind = [3, 6];
let indexes = [];
for (let value of valuesToFind) {
  if (arr.includes(value)) {
    indexes.push(arr.indexOf(value));
  }
}
console.log(indexes); // 输出：[2, 5]