How to convert array data format

Question

I have the following array in number format. Arr[12，713，6…], I am trying to convert them to [0012,0713,0006…]. I tried padstart(4,"0") but not working, anybody can help?

You do realize, `0012` as number will always be `12`. If you want `0012`, you will have to convert it to string. Try `Arr.map((num) => ("0000" + num.toString()).slice(-4) )` — Rajesh, Sep 10 '19 at 11:26
Those are some strange Unicode characters that you are using... — Mr. Polywhirl, Sep 10 '19 at 11:26
padStart does work if you convert your number to a string. `Arr.map(number => number.toString().padStart(4, "0"))` — wiesson, Sep 10 '19 at 11:29
@Rajesh The commas that OP used are not standard... `Arr[12，713，6…]` They are using a full-width comma instead of a standard comma... https://www.fileformat.info/info/unicode/char/ff0c/index.htm — Mr. Polywhirl, Sep 10 '19 at 11:33

score 0 · Answer 1 · answered Sep 10 '19 at 11:29

var array = [12,713,6];
var newArray = [];

array.forEach(function(element) {
  newArray.push(element.toString().padStart(4,0));
});

console.log(newArray);

//Or with array.map (requires ECMAScript 5)
console.log(array.map(number => number.toString().padStart(4, "0")))

score 0 · Answer 2 · answered Sep 10 '19 at 11:30

0

You can map your array with numbers, before you use padStart just make sure that the element is a string.

const arr = [1, 2, 323, 32].map((el) => el.toString().padStart(4, '0'));
console.log(arr);

answered Sep 10 '19 at 11:30

Nicolae Maties

2,476
1
16
26

score 0 · Answer 3 · answered Sep 10 '19 at 11:30

You can pad a number by adding n-number of zeroes before the value and then clipping the string n-places from the beginning.

const padLeft = (v, ch, n) => (ch.repeat(n) + v).substr(-n);

let input = [ 12, 713, 6 ];
let output = input.map(x => padLeft(x, '0', 4));

console.log(output);

How to convert array data format

3 Answers3