Nov 5, 2025
diff --git a/Data-Structures/Array/TwoSum.js b/Data-Structures/Array/TwoSum.js
 /**
 * This function will accept an array and a target value,
 * and return the indexes of the two numbers that add up to the target.
 * If no such pair exists, it returns null.
 * @param {number[]} nums - array of numbers
 * @param {number} target - target sum
 * @returns {number[] | null} - array containing two indexes or null
 */

 const twoSum = (nums, target) => {
  for (let i = 0; i < nums.length; i++) {
    for (let j = i + 1; j < nums.length; j++) {
      if (nums[i] + nums[j] === target)
        return [i, j]
    }
  }
  return null
 }

 export { twoSum }
diff --git a/Data-Structures/Array/test/TwoSum.test.js b/Data-Structures/Array/test/TwoSum.test.js
 import { twoSum } from '../TwoSum'

 describe('twoSum tests', () => {
  it('should return indices for a normal case', () => {
    const nums = [2, 7, 11, 15]
    const target = 9
    expect(twoSum(nums, target)).toEqual([0, 1])
  })

  it('should return indices when pair is in middle', () => {
    const nums = [1, 4, 6, 8, 5]
    const target = 11
    expect(twoSum(nums, target)).toEqual([2, 4])
  })

  it('should handle negative numbers', () => {
    const nums = [-3, 4, 3, 90]
    const target = 0
    expect(twoSum(nums, target)).toEqual([0, 2])
  })

  it('should return null if no pair found', () => {
    const nums = [1, 2, 3, 4]
    const target = 100
    expect(twoSum(nums, target)).toBeNull()
  })

  it('should work with duplicate numbers', () => {
    const nums = [3, 3]
    const target = 6
    expect(twoSum(nums, target)).toEqual([0, 1])
  })
 })
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,20 @@
		/**
		* This function will accept an array and a target value,
		* and return the indexes of the two numbers that add up to the target.
		* If no such pair exists, it returns null.
		* @param {number[]} nums - array of numbers
		* @param {number} target - target sum
		* @returns {number[] \| null} - array containing two indexes or null
		*/

		const twoSum = (nums, target) => {
		for (let i = 0; i < nums.length; i++) {
		for (let j = i + 1; j < nums.length; j++) {
		if (nums[i] + nums[j] === target)
		return [i, j]
		}
		}
		return null
		}

		export { twoSum }
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,33 @@
		import { twoSum } from '../TwoSum'

		describe('twoSum tests', () => {
		it('should return indices for a normal case', () => {
		const nums = [2, 7, 11, 15]
		const target = 9
		expect(twoSum(nums, target)).toEqual([0, 1])
		})

		it('should return indices when pair is in middle', () => {
		const nums = [1, 4, 6, 8, 5]
		const target = 11
		expect(twoSum(nums, target)).toEqual([2, 4])
		})

		it('should handle negative numbers', () => {
		const nums = [-3, 4, 3, 90]
		const target = 0
		expect(twoSum(nums, target)).toEqual([0, 2])
		})

		it('should return null if no pair found', () => {
		const nums = [1, 2, 3, 4]
		const target = 100
		expect(twoSum(nums, target)).toBeNull()
		})

		it('should work with duplicate numbers', () => {
		const nums = [3, 3]
		const target = 6
		expect(twoSum(nums, target)).toEqual([0, 1])
		})
		})