Javascript 在特定索引的数组中拆分字符串

Question

I have this array of strings.

const numbersArray = ['1000','10000','100000']

My goal is to split each one of them on specific index for example: output of 1000 should be 1,000 and etc...

Here is what i have right now:

  const splitArrayHandler = (arr) =>{
  for (let i = 0; i < arr.length; i++) {
    let indexOfSymbol = Math.round(arr[i].length / 3)
    return splitAtIndex(arr[i],indexOfSymbol)
  }
}

const splitAtIndex = (value,index) => {
  return value.substring(0,index) + ',' + value.substring(index)
}

splitArrayHandler(numbersArray)

The first function splitArrayHandler loops through my array,finds specific index of the symbol in the string and then function splitAtIndex does the rest of the hard work.

The problem is only first element of the string is passing to the splitAtIndex function and I dont understand why. any suggestions please?

 const numbersArray = ['1000','10000','100000'] const splitArrayHandler = (arr) =>{ for (let i = 0; i < arr.length; i++) { let indexOfSymbol = Math.round(arr[i].length / 3) return splitAtIndex(arr[i],indexOfSymbol) } } const splitAtIndex = (value,index) => { return value.substring(0,index) + ',' + value.substring(index) } splitArrayHandler(numbersArray)

Answer 1

Use Intl.NumberFormat for the job. No need for string parsing / manipulating:

 const numbersArray = ['1000', '10000', '100000', '654654686156', '1000.66', '10e14', '0xFFFF']; const format = new Intl.NumberFormat('en-US').format; const formattedNumbers = numbersArray.map(Number).map(format); console.log(formattedNumbers);

Answer 2

You might use regular expression and map function (though there is no real difference between map and hard coded loop)

const numbersArray = ['1000','10000','100000']
function addComa(x) {
    return x.replace(/\B(?=(\d{3})+(?!\d))/g, ',')
}
const resolved = numbersArray.map(addComma)
console.log(resolved) // ['1,000','10,000','100,000']

Answer 3

You are breaking the loop by returning the splitAtIndex function. Create another array and push the results to it.

const splitArrayHandler = (arr) =>{
  let arr2 = []
  for (let i = 0; i < arr.length; i++) {
    let indexOfSymbol = Math.round(arr[i].length / 3)
    arr2.push(splitAtIndex(arr[i],indexOfSymbol))
  }
  return arr2
}