20250623 17:00 Chapter 4 : Switching Decisions in C

                              

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Things switch can’t do:

1. You can't use decimal numbers (float):

   switch(3.14) // ❌ Not allowed
   

   switch only works with whole numbers or characters.

2. You can't use math with variables in case:

   case a + 3: // ❌ Not allowed
   

   case values must be fixed numbers, not something that changes.

3. You can't repeat the same value in two cases:

   case 3: 

         case 1 + 2: // ❌ This is like writing case 3 again!

So why use switch?

Because it’s faster when you have many options to choose from.

But if you need:

• decimal numbers

• value ranges (like x < 5)

• or changing values in case

Then go with if-else, it’s more flexible.

The Dangerous GOTO

"GOTO" is like teleportation — fast, but very confusing.

Why avoid goto?

• Makes code hard to read

• Confuses the flow of logic

• Harder to debug

• Like putting trapdoors in your code

Example:

int goals;
scanf("%d", &goals);

if (goals <= 5)
    goto sorry;
else {
    printf("Time to switch careers!\n");
    exit(0);
}

sorry:
printf("To err is human!\n");

What’s happening?

• If goals <= 5, it jumps to sorry label.

• Otherwise, it exits the program.

• goto is used to jump directly to a part of code.

But wait — there’s always a cleaner way.

When is goto okay-ish?

for (i = 1; i <= 3; i++)
  for (j = 1; j <= 3; j++)
    for (k = 1; k <= 3; k++)
      if (i == 3 && j == 3 && k == 3)
        goto out;
      else
        printf("%d %d %d\n", i, j, k);

out:
printf("Escaped the loop!\n");

goto out; jumps out of all loops like hitting an emergency button!

goto is like a fire exit — use it only when there’s no better way.

Try break or a flag first. They're cleaner and safer!