Implement Insertion Sort

JavaScript
1

Tell us what’s happening:

Your code so far

// I watched the hint, there is one line out of my understanding...
function insertionSort(array) {
  for (let i = 1; i < array.length; i++){
    let curr = array[i];
    for (var j = i-1; j >= 0 && array[j] > curr; j--){
      array[j+1] = array[j];
    }
    array[j+1] = curr;  //why the j can be used here? Does it should be only valid in the inner for loop ?
  }
  return array;
}

// test array:
// [1, 4, 2, 8, 345, 123, 43, 32, 5643, 63, 123, 43, 2, 55, 1, 234, 92]

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36.

Link to the challenge:
https://learn.freecodecamp.org/coding-interview-prep/algorithms/implement-insertion-sort

3

that inner for loop is not a local scope? I thought the variable is declared in the scope of the inner for loop…

4

It is declared in the for loop, but it is local to the function. It is the nature of var. If you use let, then it creates a block scope within the for loop.