The following function compares a value against an array and goes through the elements of the array until finds an element that is smaller than the comparison value. As a result it should return the index of that element where condition was met. In this example it should return the index of 4 (with value of 5). I store this index in lowestNumberIndex but can only access it within the scope of last if() function. How can I access it outside the for loop? Notice that I have initiated the object outside of the for loop.

function findLowerIndex () {

  let firstArray = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
  let compareValue = [6];

  var lowerNumber = null;
  var lowestNumberIndex = null;

  for (i=firstArray.length-1; i>0; i--) {
    lowerNumber = firstArray[i];
    if (lowerNumber < compareValue) {
      lowestNumberIndex = i;
      return;
    }
  }
}

• In case you are wondering, I need to have the for loop in reverse format because this is part of a larger code and the dataset is organized in a way that doing it backwards ensures efficiency of run.

CodePudding user response：

You could take the index for looping and as result. For the comparing value use the value without wrapping it in an array.

function findLowerIndex() {
    const
        firstArray = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
        compareValue = 6;

    let index = firstArray.length;

    while (index--) {
        if (firstArray[index] < compareValue) break;
    }
    // use the found index
    return index;
}

console.log(findLowerIndex());

CodePudding user response：

So thanks to all the comments and solutions I figured what the problem was. The problem was that I did not know using return jumps you out of the whole function. Using break instead worked!