Why is a negative case in try catch block returning 'Undefined'

When I try to get value of a key not there in map in the try catch block why is it throwing undefined.

I can check if the map has the key with has() method but why is the below code throwing undefined instead of printing the log as "Error"

var n="0";

try{

var monthDaysMap = new Map([

["1","31"],

["2","28"],

["3","31"],

["4","30"],

["5","31"],

["6","30"],

["7","31"],

["8","31"],

["9","30"],

["10","31"],

["11","30"],

["12","31"]

]);

console.log(monthDaysMap.get(n));

}catch(error){

console.log("Error");

}