Easy if-else OR switch-case

[audinue]

I wonder... Which is easier if-else statement or switch-case statement to be learned for first?

[laserlight]

I think that if-else statements may be easier to learn since you would not also need to explain the concept of fall through (assuming that the programming language's switch construct has such a feature) while explaining the concept of control flow branching.

[audinue]

However, I just confused with if (nested statement) which is a part of if statement.

For instance, I'll give this easy-to-understand (I think) for my friends...

bool hungry = true;
if( hungry ) {
  print( "Eating some food..." );
}
print( "Go to campus!" );

That's mean whenever you hungry you'll eat some food first, even if you're not you will still go to the campus.

But, I still don't get the *right* example (analogy) for the nested one.

bool hungry = true;
if( hungry ) {
  if( momCooking ) {
    print( "Eating some food..." );
  } else {
    print( "Go to restaurant to eat." );
  }
}
print( "Go to campus!" );

Obviously the code above still can be changed to:

bool hungry = true;
if( hungry && momCooking ) {
    print( "Eating some food..." );
} else if( hungry && !momCooking ) {
    print( "Go to restaurant to eat." );
}
print( "Go to campus!" );

Ohhh yeah... I don't get it.

[maxorator]

bool hungry = true;
if( hungry && momCooking ) {
    print( "Eating some food..." );
} else if( hungry && !momCooking ) {
    print( "Go to restaurant to eat." );
}
print( "Go to campus!" );

Ohhh yeah... I don't get it.

That bold part is not necessary anymore, since mom obviously isn't cooking.

[jEssYcAt]

Actually, mom may be cooking and we just aren't hungry.

if ( hungry && momCooking )

can be false if hungry is false and momCooking is true, if hungry is true and momCooking is false, or if hungry is false and momCooking is false.

In this case, I would say it is irrelevant whether or not momCooking until we determine hungry, so the "outter" if statement should only check whether hungry is true or not. If it isn't, we don't even need to bother checking for momCooking.

bool hungry = true;
if( hungry ) {
  if( momCooking ) {
    print( "Eating some food..." );
  } else {
    print( "Go to restaurant to eat." );
  }
}
print( "Go to campus!" );

is much clearer.

I would only combine expressions in an if statement (or a [do-]while/for condition) if each expression must be resolved before we determine a course of action.

[jEssYcAt]

[edit] oops, I just noticed the bool hungry = true, so you're right in this case. However then I would say it is not useful in this case to have hungry even in the if statement since we are really only checking to see whether momCooking or not.

However, if we remove the initialization to true and instead assume that hungry might be true or false (determined earlier in the code), then my statements are valid.[/edit]

[edit2]gah, sorry for the double post, hit the wrong button.[/edit2]