217. Contains Duplicate

 Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

 

Example 1:

Input: nums = [1,2,3,1]
Output: true

Example 2:

Input: nums = [1,2,3,4]
Output: false

Example 3:

Input: nums = [1,1,1,3,3,4,3,2,4,2]
Output: true

 

Constraints:

• 1 <= nums.length <= 105
• -109 <= nums[i] <= 109

In JS:

var containsDuplicate = function(nums) {

    nums.sort(function(a, b){return a - b});

    let count = 0;

    for(let i=0; i<nums.length; i++){

      if(nums[i] == nums[i+1]) count++;

    }

    if(count > 0) return true;

    else return false;

};