Finders Keepers confusion

I am wondering how the func num=> num % 2 ===0 works? Why the zero at the very end? My last question is how does the return undefined work at its specific location? Why is it placed after two }} and before one }. Thank you!

   **Your code so far**
function findElement(arr, func) {
 let num = 0;
 for (let i =0; i<arr.length; i++){
   num = arr[i]
if(func(num)){
return num
}
 }
 return undefined;
}

console.log(findElement([1, 2, 3, 4], num => num % 2 === 0));
   **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.5005.63 Safari/537.36

Challenge: Finders Keepers

Link to the challenge:

That function says “return true if the remainder of dividing num by 2 is 0”.

Try formatting the code by right clicking the editor and selecting the format option, then you can see where the return statement lines up easier.