freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/drop-it.english.md

id, title, challengeType, forumTopicId

id	title	challengeType	forumTopicId
a5deed1811a43193f9f1c841	Drop it	5	16010

Description

Given the array arr, iterate through and remove each element starting from the first element (the 0 index) until the function func returns true when the iterated element is passed through it. Then return the rest of the array once the condition is satisfied, otherwise, arr should be returned as an empty array.

Instructions

Tests

tests:
  - text: <code>dropElements([1, 2, 3, 4], function(n) {return n >= 3;})</code> should return <code>[3, 4]</code>.
    testString: assert.deepEqual(dropElements([1, 2, 3, 4], function(n) {return n >= 3;}), [3, 4]);
  - text: <code>dropElements([0, 1, 0, 1], function(n) {return n === 1;})</code> should return <code>[1, 0, 1]</code>.
    testString: assert.deepEqual(dropElements([0, 1, 0, 1], function(n) {return n === 1;}), [1, 0, 1]);
  - text: <code>dropElements([1, 2, 3], function(n) {return n > 0;})</code> should return <code>[1, 2, 3]</code>.
    testString: assert.deepEqual(dropElements([1, 2, 3], function(n) {return n > 0;}), [1, 2, 3]);
  - text: <code>dropElements([1, 2, 3, 4], function(n) {return n > 5;})</code> should return <code>[]</code>.
    testString: assert.deepEqual(dropElements([1, 2, 3, 4], function(n) {return n > 5;}), []);
  - text: <code>dropElements([1, 2, 3, 7, 4], function(n) {return n > 3;})</code> should return <code>[7, 4]</code>.
    testString: assert.deepEqual(dropElements([1, 2, 3, 7, 4], function(n) {return n > 3;}), [7, 4]);
  - text: <code>dropElements([1, 2, 3, 9, 2], function(n) {return n > 2;})</code> should return <code>[3, 9, 2]</code>.
    testString: assert.deepEqual(dropElements([1, 2, 3, 9, 2], function(n) {return n > 2;}), [3, 9, 2]);

Challenge Seed

function dropElements(arr, func) {
  return arr;
}

dropElements([1, 2, 3], function(n) {return n < 3; });

Solution

function dropElements(arr, func) {
  while (arr.length && !func(arr[0])) {
    arr.shift();
  }
  return arr;
}