change the value of object inside a list

My code’s output is like this:

let myArray = [{"num": "2", "name": "Jhon"}, {"num": "1", "name": "Sara"}, {"num": "2", "name": "Domnic"}, {"num": "3", "name": "Bravo"}]

How can I access value of num in each field of the list and if num: 2, change its value to 5?