Thread: How do you read this syntax?

Hi everyone,

I am preparing for a Java exam at the moment and I came across the following syntax and don't understand how to read it or what exactly it does:

i = (j>1)?2:1;

the whole code block where this is in is as follows:

int i, j=1;
	i = (j>1)?2:1;
	switch(i){
	case 0: System.out.println(0); break;
	case 1: System.out.println(1);
	case 2: System.out.println(2); break;
	case 3: System.out.println(3); break;
	}

The print out from this is
1
2

Please remember to include code tags.

Code:

int i, j=1;
i = (j>1)?2:1;
switch(i){
case 0: System.out.println(0); break;
case 1: System.out.println(1);
case 2: System.out.println(2); break;
case 3: System.out.println(3); break;
}

Is there supposed to be a break statement after case 1: System.out.println(1);?

I'm not sure how to read i = (j>1)?2:1, so I'm curious what the answer is too.

But, if I had to take a guess, I would say this:

the statement (j>1) is a boolean, which would result in false since j==1.
the ? character probably indicates a decision for the value of the int based on the preceding boolean.
the statement 2:1 probably gives options based on the boolean result, where before the colon is the true value and after the colon is the false value.

Which means that i = (j>1)?2:1 will make i==1, which would work with your switch statement. Then, since case 1: System.out.println(1); doesnt include a break statement, it goes to the next switch statement afterwards, which is case 2: System.out.println(2); break;, which would give the printout:

1
2

If I'm right, then that is some damn good guessing. If I'm wrong, I think I did a good job justifying it.