how to edit an array in js code example

Example 1: modify array elements javascript

Using a FOR loop, write a function addNumber which adds the argument n to each 
number in the array arr and returns the updated arr:
const addNumber=(arr, n)=>{  
  let arr1=[];
  for(let i=0;i<Math.max(arr.length);i++){
    arr1.push((arr[i]||0)+n)
  }
  return arr1;
} 
console.log(addNumber([4, 5, 6], 7)); // expected log [11, 12, 13]

Example 2: how to modify an array

let schedule = ['I', 'have', 'a', 'meeting', 'with'];
// adds 3 new elements to the array
schedule.splice(5, 0, 'some', 'clients', 'tommorrow');
console.log(schedule); 
// ["I", "have", "a", "meeting", "with", "some", "clients", "tommorrow"]