Why is a number displayed and not undefined?

Question

JavaScript

Hello!
Explain plz.

function num(i) {
  
  var i = i;
  console.log(i);

}
num(3);

Why does this example output 3 and not undefined?
I can not understand how the interpreter parses such code - in what sequence?

Answer 1

Maybe this post will shed some light on the situation.

for each variable (var)
- a VO property is created with the name of the variable, and the value is undefined; if a property with the same name already existed in the VO, it remains untouched.

Answer 2

So where does undefined come from?
After all, your code is fundamentally no different from this:

var foo = i;
console.log(foo);

Code in most programming languages ​​is parsed from right to left. A local variable and an argument are two different areas of memory, so one does not overwrite the other.