javascriptarrays

Remove n-th elements from the end of an array

I have an array like this:

array = [1,2,3,4,5,6,7,8]

and I want to remove for example the 4 last values so as my array becomes this:

array = [1,2,3,4]

I used array.splice(array.length - 4, 1) but it didn't work. Any ideas?

Solution

  • You can use the function slice as follow:

    .slice(0, -4)

    This approach doesn't modify the original Array

    //                                    +---- From 0 to the index = (length - 1) - 4,
//                                    |     in this case index 3.
//                                  vvvvv
var array = [1,2,3,4,5,6,7,8].slice(0, -4);
console.log(array);
    .as-console-wrapper { max-height: 100% !important; top: 0; }

    This approach modifies the original Array

    var originalArr = [1, 2, 3, 4, 5, 6, 7, 8];

//                     +---- Is optional, for your case will remove 
//                     |     the elements ahead from index 4.
//                     v
originalArr.splice(-4, 4);
console.log(originalArr);

//----------------------------------------------------------------------

originalArr = [1, 2, 3, 4, 5, 6, 7, 8];
//                  +---- Omitting the second param.
//                  |     
//                  v
originalArr.splice(-4);
console.log(originalArr);
    .as-console-wrapper { max-height: 100% !important; top: 0; }

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