Java Array, Finding Duplicates

Question

I have an array, and am looking for duplicates.

duplicates = false;
for(j = 0; j < zipcodeList.length; j++){
    for(k = 0; k < zipcodeList.length; k++         


        

Answer 1

@andersoj gave a great answer, but I also want add new simple way

    private boolean checkDuplicateBySet(Integer[] zipcodeList) {
        Set zipcodeSet = new HashSet(Arrays.asList(zipcodeList));
        if (zipcodeSet.size() == zipcodeList.length) {
            return true;
        }
        return false;
    }

In case zipcodeList is int[], you need convert int[] to Integer[] first(It not auto-boxing), code here

Complete code will be:

    private boolean checkDuplicateBySet2(int[] zipcodeList) {
        Integer[] zipcodeIntegerArray = new Integer[zipcodeList.length];
        for (int i = 0; i < zipcodeList.length; i++) {
            zipcodeIntegerArray[i] = Integer.valueOf(zipcodeList[i]);
        }

        Set zipcodeSet = new HashSet(Arrays.asList(zipcodeIntegerArray));
        if (zipcodeSet.size() == zipcodeList.length) {
            return true;
        }
        return false;
    }

Hope this helps!