contain duplicates

Author: AnwarHossainSR

202-isHappy.js

@@ -0,0 +1,30 @@
+// /**
+// * @param {number[]} nums
+// * @return {boolean}
+// */
+// var containsDuplicate = function (nums) {
+// let unique = [];
+// for (let i = 0; i < nums.length; i++) {
+// if (i == 0) {
+// unique.push(nums[i]);
+// } else {
+// if (unique.includes(nums[i])) {
+// return true;
+// } else {
+// unique.push(nums[i]);
+// }
+// }
+// }
+// return false;
+// };
+
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var containsDuplicate = function (nums) {
+ let unique = new Set(nums);
+ return unique.size !== nums.length;
+};
+
+console.log(containsDuplicate([1, 2, 3, 4]));