why I get Different result in switch statements

Question

I am learning JavaScript and currently I build simple tip calculator using function and switch statement. Basically, tip 20% of the bill when the bill is less than $50, 15%

Answer 1

switch case does not work the way you are using it.

switch(test){
    case a:
        break;
    case b:
        break;
    case c:
        break;
}

compares the value of test to the value of a, then b and so on

so in your first code example it compares 124 with the value/output of (bill > 0 && bill < 50) which is false

so you are comparing integers with booleans.
To make ranges work you have to do it like in your second example.

Stackoverflow post I found: https://stackoverflow.com/a/5619997/7584725