freeCodeCamp/sum-all-numbers-in-a-range.english.md at 5cd850f666dd02c0b2dd2deb9c9a4705d4fc7df2

Oliver Eyton-Williams f1c9b08cf3 fix(curriculum): add isHidden: false to challenges

This includes certificates (where it does nothing), but does not
include any translations.

2020-05-25 16:25:19 +05:30

1.5 KiB

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id, title, isRequired, challengeType, isHidden, forumTopicId

id	title	isRequired	challengeType	isHidden	forumTopicId
a3566b1109230028080c9345	Sum All Numbers in a Range	true	5	false	16083

Description

We'll pass you an array of two numbers. Return the sum of those two numbers plus the sum of all the numbers between them. The lowest number will not always come first.

For example, sumAll([4,1]) should return 10 because sum of all the numbers between 1 and 4 (both inclusive) is 10.

Instructions

Tests

tests:
  - text: <code>sumAll([1, 4])</code> should return a number.
    testString: assert(typeof sumAll([1, 4]) === 'number');
  - text: <code>sumAll([1, 4])</code> should return 10.
    testString: assert.deepEqual(sumAll([1, 4]), 10);
  - text: <code>sumAll([4, 1])</code> should return 10.
    testString: assert.deepEqual(sumAll([4, 1]), 10);
  - text: <code>sumAll([5, 10])</code> should return 45.
    testString: assert.deepEqual(sumAll([5, 10]), 45);
  - text: <code>sumAll([10, 5])</code> should return 45.
    testString: assert.deepEqual(sumAll([10, 5]), 45);

Challenge Seed

function sumAll(arr) {
  return 1;
}

sumAll([1, 4]);

Solution

function sumAll(arr) {
  var sum = 0;
  arr.sort(function(a,b) {return a-b;});
  for (var i = arr[0]; i <= arr[1]; i++) {
    sum += i;
  }
  return sum;
}

1.5 KiB Raw Blame History