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Filter range "in place"

importance: 4

Write a function filterRangeInPlace(arr, a, b) that gets an array arr and removes from it all values except those that are between a and b. The test is: a ≤ arr[i] ≤ b.

The function should only modify the array. It should not return anything.

For instance:

let arr = [5, 3, 8, 1];

filterRangeInPlace(arr, 1, 4); // removed the numbers except from 1 to 4

alert( arr ); // [3, 1]

Open a sandbox with tests.

function filterRangeInPlace(arr, a, b) {

  for (let i = 0; i < arr.length; i++) {
    let val = arr[i];

    // remove if outside of the interval
    if (val < a || val > b) {
      arr.splice(i, 1);
      i--;
    }
  }

}

let arr = [5, 3, 8, 1];

filterRangeInPlace(arr, 1, 4); // removed the numbers except from 1 to 4

alert( arr ); // [3, 1]

Open the solution with tests in a sandbox.