Given the affairs list for a certain date. Using only FOR loops an IF display all affairs for 2018. Display all affairs for the 12 month of 2018

Given the affairs list for a certain date:

let affairs = {
    '2019-12-31': ['affairs Array'],
    '2018-11-29': ['affairs Array'],
    '2018-11-30': ['affairs Array'],
    '2018-12-27': ['affairs Array'],
    '2019-12-29': ['affairs Array'],
    '2019-12-30': ['affairs Array'],
    '2018-12-30': ['affairs Array'],
    '2018-12-31': ['affairs Array'],
}

First question: Display all affairs for 2018.

Second question: Display all affairs for the 12 month of 2018.

Could you please help me with this task? I have no idea :(