Javascript:TrimLeft & TrimRight

function trimLeft(str) {

  if (typeof str !== 'string') {

    throw new TypeError('Expected a string');

  }

  return str.replace(/^\s+/, '');

}

function trimRight(str) {

  if (typeof str !== 'string') {

    throw new TypeError('Expected a string');

  }

return str.replace(/\s+$/, '');

}

let input = '   Hello, World!   ';

let trimmedLeft = trimLeft(input);

console.log("'" + trimmedLeft + "'"); // Output: 'Hello, World!   '

let trimmedRight = trimRight(input);

console.log("'" + trimmedRight + "'"); // Output: '   Hello, World!'

Javascript:Leet Code -Find pair of number in array whose sum equal to target

Find a pair of number from array whose sum is equal to target

nums = [2, 7, 11, 15]

target = 9

function targetSumPair(nums, target) {

    arr = []

    for (let i = 0; i < nums.length; i++) {

        for (let j = i + 1; j < nums.length; j++) {

            if(nums[i]>target && nums[j] > target) continue

            if (nums[i] + nums[j] == target) {

                return [i, j]

            } else {

                console.log(`i=${nums[i]} j=${nums[j]}`)

            }

        }

    }

}

console.log(targetSumPair(nums,target))

Expected Optimized Way:

function targetSumPair(nums, target) {

    let obj = {};

    for (let i = 0; i < nums.length; i++) {

        let complement = target - nums[i];

        if (obj[complement] !== undefined) {

            return [obj[complement], i];

        }

        obj[nums[i]] = i;

    }

}

console.log(targetSumPair([2, 7, 11, 15], 9));{