sort an array and remove duplicates code example

Example 1: remove duplicates from array

let chars = ['A', 'B', 'A', 'C', 'B'];
let uniqueChars = [...new Set(chars)];

console.log(uniqueChars);

output:
[ 'A', 'B', 'C' ]

Example 2: remove duplicates from sorted array

// Java
public int removeDuplicates(int[] nums) {
    if (nums.length == 0) return 0;
    int i = 0;
    for (int j = 1; j < nums.length; j++) {
        if (nums[j] != nums[i]) {
            i++;
            nums[i] = nums[j];
        }
    }
    return i + 1;
}

Example 3: remove duplicates in sorted array python

# function for removing duplicates
def removeDuplicate(arr, n):
    j = 0
    
    # traverse elements of arr
    for i in range(0, n-1): 
        # if ith element is not equal to (i+1)th element, then store ith value in arr[j]
        if (arr[i] != arr[i+1]):
            arr[j] = arr[i]
            j = j+1

    # store last value of arr in arr[j]
    arr[j] = arr[n-1]
    j = j+1
    
    # print first j elements of array arr
    for i in range(0, j):
        print("%d"%(arr[i]), end = " ")

arr = [1, 3, 5, 5, 7, 9]
n = len(arr)
# calling function when number of elements in array is greater than 1
if (n > 1):
    removeDuplicate(arr, n)