If-else working, switch not

Question

I am making an app that has a grid of images with text and each one opens a different activity. It works fine but just for design purposes I want to replace my if-else

Answer 1

You need to break; after each branch:

switch (position) {
    case 0:
        textView.setText(R.string.zero);
        break; // <-- here
    // etc
}

Legitimate uses of switch when you don't break exist, those are called fall throughs; or because you return or throw.:

switch (someNumber) {
    case 0:
        return 0; 
        // no need for break here
    case 1:
        throw new IllegalArgumentException();
        // no need to break here
    case 2:
        System.out.println("Oh, I got two!");
        // fall through
    case 3:
        return 3;
    default:
        System.out.println("Meh")
        // No need to break: last possible branch
}

return -1;

will return 3 even if you enter 2.

But otherwise you need to break.

Answer 2

Using a break statement after each case should fix the problem. I would also use a default statement as well after the last case.

Answer 3

Each break statement terminates the enclosing switch statement. Control flow continues with the first statement following the switch block. The break statements are necessary because without them, statements in switch blocks fall through: All statements after the matching case label are executed in sequence, regardless of the expression of subsequent case labels, until a break statement is encountered.

Switch is faster than if-else statement

Bottom line : Default is optional(works like else statement in switch), Break is mandatory.

Interesting fact: you won't see any compilation error, even if you forgot to place the break statement.

Answer 4

You need to break; after each statement in a case, otherwise execution flows down (all cases below the one you want will also get called), so you'll always get the last case.

switch(position) {
case 0:
    textView.setText(R.string.zero); 
    break; 
case 1:
    textView.setText(R.string.one);
    break; 
case 2:
    textView.setText(R.string.two);   
    break;  
case 3:
    textView.setText(R.string.three);
    break; 
case 4:
    textView.setText(R.string.four); 
    break; 
}

Here's the official tutorial explaining when to and when not to use break;.

Answer 5

This is the solution. You need to use break to avoid going through each case:

switch(position)
case 0:
   textView.setText(R.string.zero);    
   break;
case 1:
   textView.setText(R.string.one);
   break;
case 2:
   textView.setText(R.string.two);  
   break;  
case 3:
   textView.setText(R.string.three);
   break;
case 4:
   textView.setText(R.string.four);    
   break;

I would recommend to read the oracle documentation about the switch statement.

Answer 6

The switch needs a break with in each case. But in your case it could be done much simpler by defining an array as shown below.

String values = {R.string.zero, R.string.one, R.string.two, ... };

Use this to populate textView : textView.setText(values[position]);