I want to print the last 'n' elements of an array

Question

I am writing a JavaScript function to get the last 'n' elements of the array. If array has 6 elements and if user gives 4, it has to return last 4 elements. If user gives ‘n’ which is greater than the number of elements in the array, then it should return all elements.

The problem is if If the array has 8 elements and I give number 10. The result is : undefined undefined 1 2 3 4 5 6 7 8

I want to display only the numbers without "undefined".

Thanks

HTML code

The array is :

1,2,3,4,5,6,7,8

        <br>
        x:
        <input type="number" id="x" value="2" >
        <br>
        <button onclick="elements()"> Get the elements </button>

        <p id="result"></p>

    <script src="ex10.js"></script>

JavaScript code

 var Elements = new Array(1,2,3,4,5,6,7,8);

    function elements(){
    var x = document.getElementById("x").value;

    for(var i=Elements.length - x; i <=Elements.length-1; i++)
    {
    document.getElementById("result").innerHTML += Elements[i] + " ";
    }

}

Answer 1

You could take slice with a negative count from the end. Then join the elements for a formatted output.

Some links:

• Array#slice
• Array#join

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

console.log(array.slice(-4).join(' '));

Answer 2

Try using .slice method with a negative start index:

var Elements = new Array(1,2,3,4,5,6,7,8);

var last4 = Elements.slice(-4)

console.log(last4)