javascript - Questions about typeof of js

Question

The return result of typeof I saw today is actually an integer. And why the results of the results in the picture are 1.

Answer 1

1. Because typeof has a higher priority
2. Or because the addition operator has a higher priority

Answer 2

var a=true;
console.log(a);//返回true
console.log(typeof a);//返回boolean
console.log(typeof(typeof a));//返回"string"

Essentially typeof a ? 1 : 2 can be written like this:

"boolean" ? 1:2

And this ternary expression calls Boolean() to convert the string type, that is:
Boolean("boolean") ====>true
So the return is 1.
You can try assigning a to false, and the return value will still be 1:

var a=false;
typeof a ? 1 : 2

Answer 3

This statement is compiled like this
(typeof a)? 1 : 2
When it was compiled, it was changed to this form, and this is the result. Ternary operator

Answer 4

Nothing wrong

Boolean('string') => true

Answer 5

Taking your example, the
ternary operator, when typeof a is true, returns 1, and when
typeof a is false, it returns 2.
The first 100 + a; has been type converted, so 100 + a = 101,
so results also returns 1