Basic query on passing this to a function

Question

I am trying to understand JavaScript this better.

function foo() {
    console.log(this);
}
// normal function call
foo(); // `this` will refer to `window`
         


        

Answer 1

 var that = this;
 function foo(that){
   console.log(that):
 }
 foo();

foo() parameter is missing.

so function foo(that) will be undefined.

To make it work

 foo(that)