Arrow function expression =>

JavaScript
1

Hi everyone.
According to MDN, when the only statement in an arrow function is return, we can remove return and remove the surrounding curly brackets, e.g.

const sum = (x,y)=>{return x  + y;} // can be turned into
const sum = (x,y ) => x + y  ;

Consider the following example

const array = [1, 2, 3, 4, 5];
console.log(array.some((element) => {return element % 2 === 0;}));   
//output =true

as (element) => {return element % 2 === 0;} have one statement only , we can simplify it into (element) => element % 2 === 0;
But when I put it back to the example, error occur

console.log(array.some((element) =>  element % 2 === 0;));
//error: missing ) after argument list

However if I delete the ; after 0 , it works again

console.log(array.some((element) =>  element % 2 === 0));
//output =true

letting the function to x also works

let x =  (element) =>  element % 2 === 0;   // ; is NOT deleted in here
console.log(array.some(x)) 
//output =true

my question is

  1. Why deleting the ; works ? and
  2. Why letting the function ( the ; is NOT deleted) to x also works without deleting the ; ? Thank you. Sorry for my poor English
2

the semicolon ; means end of statement
when you assign the function to a variable, that is a statement, and it ends after the function definition

instead when you are giving arguments to a function or method, you can’t end the statement before ending the list of arguments, so in that case gives a syntax error