A function that joins two arrays JS

November 2, 2022

I need to write a function combineArray(arr1, arr2), which takes 2 arrays, and returns a new array consisting only of numeric elements of arrays arr1 and arr2.
For example:

 combineArray([12, "User01", 22, true, -8], ["Index", 6, null, 15]));  result --> [12, 22, -8, 6, 15]

I tried to do it like this:

function combineArray(arr1, arr2) {
    let numArr = [];
    let newArr = arr1.concat(arr2);
    for(let i = 0; i < newArr.lenght; i++){
        if(typeof newArr[i] == "number") numArr.push(newArr[i]);
    }
    return numArr
}

let result = combineArray([12, "User01", 22, true, -8], ["Index", 6, null, 15])
console.log(result)

But my function returns empty array.

>Solution :

You can do it like this:

function returnNums(arr1, arr2) {
  let numArr = []
  for (const val of arr1) {
    if (typeof val === 'number') numArr.push(val)
  }
  for (const val of arr2) {
    if (typeof val === 'number') numArr.push(val)
  }
  return numArr;
}

console.log(returnNums([1, 2, 'a'], [3, 4, 'b']))

Also, the reason your code didn’t work is because there is a typo. It’s length, not lenght.