Add to array only once - leaving unique items

Question

I program a function that give me all values of some input checkboxes and include them into an array.

Function:

$('#area_tbl .checkbox').each(function(){
    /*for(var i = 0; i < test.length; i++){
        if(test[i].PLZ === $(this).find('.area-checkbox').val()){
            alert('Gleich');
        }else{
            alert('nicht gleich');
        }
    }*/
    test.push({PLZ:$(this).find('.area-checkbox').val()});
});

My array looks like this:

[Object { PLZ="42799"}]

That's fine!

Now I include automatically more checkboxes with more values. After that my function is refreshing and I include the 'new' values.

Now my problem is that my array looks like this:

 [Object { PLZ="42799"}, Object { PLZ="42799"}, Object { PLZ="51399"}]

You can see PLZ='42799' is twice.

I want to find the duplicate values and delete them from my array. I try it with the if clause in my function. But nothing works for me.

Possible duplicate of [Remove duplicates from an array of objects in javascript](http://stackoverflow.com/questions/2218999/remove-duplicates-from-an-array-of-objects-in-javascript) — Michał Perłakowski, Jan 13 '16 at 10:23

score 1 · Accepted Answer · answered Jan 13 '16 at 10:22

1

Assuming that value of each checkbox is unique, you need to reset the test value before running this each iterator

  test = [];
  $('#area_tbl .checkbox').each(function(){
        test.push({PLZ:$(this).find('.area-checkbox').val()});
   });

answered Jan 13 '16 at 10:22

gurvinder372

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4 hours.. and I don't get this solutions... weekend is coming. Thank you! – Alexander Kante Jan 13 '16 at 10:48

score 0 · Answer 2 · answered Jan 13 '16 at 10:24

You could use a memory

    // The memory will be a simple list with the already added elements. Firstly empty
    memory = []

    // we loop over ther checboxes
    $('#area_tbl .checkbox').each(function(){

        // we store the value
        var v = $(this).find('.area-checkbox').val();

        // If memory doesn't content the value... (its position is -1)
        if(memory.indexOf(v) == -1){

            // we store the object and we update the memory
            test.push({PLZ:v});
            memory.push(v);
        }

    });

score 0 · Answer 3 · answered Jan 13 '16 at 10:46

You could use a temporary object and look up with accessing the property:

var object= {};

$('#area_tbl .checkbox').each(function() {
    var v = $(this).find('.area-checkbox').val();
    if (!object[v]) {
        test.push({PLZ: v});
        object[v] = true;
    }
});

Add to array only once - leaving unique items

3 Answers3