JS Practice — Built-in Objects

Function.prototype.apply() — push multiple elements

📖 Usage Example

const args = [1, 2, 3]
function sum(a, b, c) { return a + b + c }
sum.apply(null, args)  // → 6

apply() is useful when arguments are already in an array.

apply() with Array.push

[].push.apply(target, source) appends all elements of source into target — useful before spread syntax.

Challenge: Use [].push.apply(arr, [2, 3]) on arr = [1] and verify arr equals [1, 2, 3].

💡 Hints (1)