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Abel Lifaefi Mbula

In this shot, we’ll discuss three ways to sum up all the numbers in a given range in JavaScript.

Our program should accept an array of two numbers as input, for example, `sumAll([1, 3])`

. Then, it should process the sum of all the numbers in the given range. It should be noted that both the numbers in the given range are inclusive, that is, `1`

and `3`

in this example. Finally, the program should return the total/sum as output, which is `6`

in the case of this example.

The lowest number will not always come first. Hence, `[3,1]`

should be treated as `[1,3]`

.

`for`

loopfunction sumAll(arr) { if (arr[0] > arr[1]) // if the highest number is on the left, sort the array arr.sort((a, b) => a - b) let sum = 0 // Initialize a variable that will be holding the sum for (let i = arr[0]; i <= arr[1]; i++) // Loop over the range sum += i return sum // return result } console.log(sumAll([3,1]))

Testing the "for" loop implementation

`.reduce()`

methodHere we will implement:

- Generate all the array items in the provided range. For example,
`[1, 4]`

=>`[1, 2, 3, 4]`

. - Get the sum by using the
`reduce()`

method.

function sumAll(arr) { if (arr[0] > arr[1]) arr.sort((a, b) => a - b) const newArr = [] for(let i = arr[0]; i <= arr[1]; i += 1) newArr.push(i) return newArr.reduce((acc, cur) => acc + cur) } console.log(sumAll([3,1]))

Testing the "reduce()" implementation

We can also use methods other than `reduce()`

to get the sum of the newly created array items.

Happy coding!

RELATED TAGS

javascript

algorithm

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Abel Lifaefi Mbula

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