Switch Cases in RobotC

VEX V5 General Discussion Technical Discussion
#1

Hey, i was wondering if someone could point me to a video or explain to me the concept and practical use of switch cases over if statements. Thank you.

#2

Here is an example using switch case.

It really makes the most sense when you expect to have more than 2 cases. The variable your comparing doesn’t have to be written in every if statement.

#3

Here’s a short video. It explains the logic of it fairly well.

#4

As for why you would use switch statements over if statements, it’s generally to avoid situations like this.

#5

Ouch, that’s painful to look at.

1 Like
#6

oof ouchie owie

#7

It makes it so that you don’t have to type nearly as much, thus you have a smaller file size and your program is easier to understand.

#8

Can someone confirm smaller file sizes? AFAIK it is the same length in machine language, because it functions exactly the same way.

Okay, so I guess the file size on the computer is smaller, but I mean on the cortex.

#9

Ya he was only talking about the c file not the compiled byte code.

#10

Compiled size and speed will depend very much on the type of switch statement, how many choices, are they sequential or a spread out. We did some analysis several months ago of the following code that may interest you.

Functionality of this code

 if ((XX == 1) || (XX == 2) || (XX == 3) || (XX == 4))
    X += 1;

and this code

  switch (XX)
  {
  case 1:
  case 2:
  case 3:
  case 4:
    X += 1;
    break;
  }

is the same

However, the switch version is around (theoretically) 6 times faster.

#11

Neat, I am very happy to have found out about switch statements this season. They are very helpful.

#12