我想使用带有 for 循环的 javascript 用数字填充数组

Question

"But I always double the numbers. so [1,1,2,2,3,3.......] how can you do that? I am looking forward to the answer. " Continuous with a number, the for loop is good. But how do I do it with double numbers?

Answer 1

To get an array to N, use:

let N = 10;
Array.from(Array(N).keys())

To double each value in any array:

[...yourArray.map(n => [n, n])].flat()

So, your solution:

 let n = 10; const a = [...Array.from(Array(n).keys()).map(k => [k, k])].flat() console.log(a)

To have it starting from 0 , not 1 , alter the mapping accordingly:

 let n = 10; const a = [...Array.from(Array(n).keys()).map(k => [k + 1, k + 1]) ].flat() console.log(a)

Arguably, the cleanest solution:

 function doubleArrayTo(n) { const a = []; for (i = 1; i <= n; i++) { a.push(i, i); } return a; } console.log(doubleArrayTo(10))

Answer 2

follow this code

var array = [];
for(int i = 0;i <= 10;i++) {
  array.push(i);
  array.push(i);//again
}

 var array = []; for (let i = 0; i <= 10; i++) { array.push(i); array.push(i); } console.log(array);