I am trying to access the last value of an array, but don't understand why this doesn't work.
const arr = [2 , 3, 6, 8];
const end = arr[ arr.length ];
console.log(end);
But when I try console logging the value it returns 4, which is what I was looking for with previous code :
console.log(arr.length);
Arrays are zero-based indexing. Which means The first element of the array is indexed by subscript of 0 and last element will be length - 1
const arr = [2 , 3, 6, 8];
const end = arr[ arr.length - 1 ];
console.log(end);
JavaScript array indexes start counting at 0. So...
arr[0] evaluates to 2
arr[1] evaluates to 3
arr[2] evaluates to 6
arr[3] evaluates to 8
arr.length evaluates to 4 because there are 4 elements in your array
arr[4] refers to the 5th element in an array, which in your example, is undefined
Arrays are 0-indexed. The last item of the array can be accessed with arr[arr.length - 1]. In your example, you're attempting to access an element at an index that doesn't exist.
Array index always start with 0 and Array length is equal to counts of element in array
value => [2,3,6,8]
indexes => [0,1,2,3]
that is why arr[4] coming undefined because there is not value at index 4.
const arr = [2 , 3, 6, 8];
const end = arr[ arr.length-1 ];
console.log(end);