Basic Data Structures: Iterate Through All an Array's Items Using For Loops

JavaScript
#1

Trying to solve this, can someone tell me why and where im going wrong

`function filteredArray(arr, elem) {
  let newArr = [];
  // change code below this line
for (let i = 0; i < arr.length; i++) {
  if (arr[i].indexOf(elem) === -1) {
    newArr = [...arr[i]];
  }
}
  // change code above this line
  return newArr;
}

// change code here to test different cases:
console.log(filteredArray([[10, 8, 3], [14, 6, 23], [3, 18, 6]], 18));`
#2

However if i change the spread operator line to newArr.push([…arr[i]]);
it works. i think im not understanding spread properly maybe.

#3

This line overwrites newArr each iteration, so the elements that were present at the end of the previous iteration are no longer there after you execute this line each time.

3 Likes
#4

you should use this syntax
for(let i=0;i<arr.length;i++){
if(arr[i].indexOf(elem)==-1){
newArr.push([…arr[i]]);
}
}

#5

You can use the code below too:

for (let i=0; i<arr.length; i++){
      if (arr[i].indexOf(elem)===-1){
      //now start forming a new array for those without elem
      newArr.push(arr[i]);
      }
  }

That works.

3 Likes
#6