Problem 20. Create an array of numbers and take input from the user to add numbers to this array.

let arr = [5, 4, 7, 8, 9, 10, 20, 30];
// console.log(typeof arr);
                    
// const a = prompt("Enter a number: ");
let a = prompt("Enter a number: ");
a = Number.parseInt(a);

// arr = arr.concat(a);
arr.push(a);
console.log(arr);

Output

output