You can initialize month as 0 and move "month++" to the beginning of the loop. This way you don't need the "--month" in the return.

You should not use getElementById method here. Just use event.target during handling the event.

Hey,

I got this issue :
TypeError: Cannot read property 'focus' of null
function selectText() {
const input = document.getElementById('input-name');
input.focus();
console.log(input);
input.setSelectionRange(0,10000);
}

At this test : handles click and change events properly

the thing is my code runs perfectly on CodeSandbox

'students' property of classes objects hold an array of 'id' values (your 'item' variable): a number referering to the 'id' property of the students objects listed in the array of students object given as second argument... you should search and find inside the object with the related 'id' property, not acccess the 'students' array directly with it (this is not an index).