Is there padEnd for Arrays in Javascript?

Question

I want my array to have minimum of n length.

If the number of elements is below the given length then I want it to be filled with given/default element until length is n.

It's very much like String padEnd function.

a=[1,2,3]
a.padEnd(6, null);
a;// [1,2,3,null,null,null];

my solution so far:

n = 10, value = {};
arr.concat(Array(n).fill(value, 0, n)).slice(0, n);

Answer 1

There is no native function to do a padEnd on Array in JavaScript. So I advice to use Object.assign to do it:

const a = [1, 2, 3];
console.log(Object.assign(new Array(5), a));
// Outputs [1, 2, 3, undefined, undefined]

We can wrap it in a function, it would be more readable. We can also choose the fill value as a optional parameter:

function padEnd(array, minLength, fillValue = undefined) {
    return Object.assign(new Array(minLength).fill(fillValue), array);
}

const a = [1, 2, 3] 
console.log(padEnd(a, 6));
// Outputs [1, 2, 3, undefined, undefined, undefined]

console.log(padEnd(a, 6, null));
// Outputs [1, 2, 3, null, null, null]