trying to figure out 'if' condition in js

Question

<script>
sayHi();
if (1) {
  function sayHi() {  console.log(1)  }
} else {
  function sayHi() {  console.log(2)  } 
}
</script> 

In chrome->console, it shows: 2

Question:

why if(1)=false ?

Answer 1

Those function definitions aren't defined at the time of execution of that condition. Both functions are hoisted at the beginning, and the latter overwrites the former.

if(1) will always evaluate to true.

This hoisting is exactly what enables you to call the function apparently before it's defined. The following code will log 1 , but note that in that case you have to call it after the condition, otherwise you'll get an error undefined is not a function .

if (1) {
  var sayHi = function() {  console.log(1)  }
} else {
  var sayHi = function() {  console.log(2)  } 
}
sayHi();