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.
nums = [array of integers]
boolean (true/false)
Example 1:
Input:
nums = [1,2,3,1]
Output:
true
Explanation:
The value 1 appears twice in the array.
Example 2:
Input:
nums = [1,2,3,4]
Output:
false
Explanation:
All elements are distinct.