我想在不使用 forEach 或过滤器或 map 的情况下打印所有元素的索引

Question

Here is my code it is giving me the same index number of the element.

I want it like this 0,1,2,3,4,5,6

let as=[1, 2, 3, 4, 5, 5,5]

for(let i=0;i<as.length;i++){
  console.log(as[i], as.indexOf(as[i]))
}

Here is my output :

1 0
2 1
3 2
4 3
5 4
5 4
5 4

Answer 1

If I understand your question correctly, you want to fetch the index of the elements available in an array. If Yes, Then you can do like this :

 let as = [1, 2, 3, 4, 5, 5,5]; const indexArray = as.map((item, index) => index); console.log(indexArray.join(','));

Answer 2

Create an array you can push the indexes into, and then create a string with join .

 const as = [1, 2, 3, 4, 5, 5, 5]; let out = []; for (let i = 0; i < as.length; i++) { out.push(i); } console.log(out.join(','));

Answer 3

Try this:

let as=[1, 2, 3, 4, 5, 5,5]

for(let i=0;i<as.length;i++){
  console.log(as[i], as.indexOf(as[i],i))
}

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