How does a compiler treats an argument value if it has two values? How does the compiler decide which one to take?

Question

If I have variable x=10 and x=12;

and I passed a parameter function value(num);

and passed an argument .... value(x); to the parameter.

how does the execution works .. will the compiler checks 10<12 or directly implements 12 is the x value in the argument.

Answer 1

As mentioned in comments. There can't be two variables with the same name and different values in the same scope. The latest assigned value will be used:

(() => {
  let x = 10;

  x= 12

  console.info(x);
})();

output : 12

https://jsfiddle.net/uv6n3hs2/