Thread: Block Statements Question

Hello,

This is my first post Just getting into learning programming and I am starting with Java.

I'm currently reading the book Teach Yourself Java in 21 days and I'm learning about List, Logic and Loops.
There is a section about Block Statements in this chapter that states that The scope of a variable defined in a block is the block that it's in. So the variable can be used only within that block.

Then it has me write a program which seems to contradict that statement.

class DayCounter {
    public static void main(String args[]) {
        int yearIn = 2012;
        int monthIn = 1;
        if (args.length > 0)
            monthIn = Integer.parseInt(args[0]);
        if (args.length > 1)
            yearIn = Integer.parseInt(args[1]);
        System.out.println(monthIn + "/" + yearIn + " has "
          + countDays(monthIn, yearIn) +  " days.");
    }
 
    static int countDays(int month, int year) {
        int count = -1;
        switch (month) {
            case 1: 
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12:
                count = 31;
                break;
            case 4:
            case 6:
            case 9:
            case 11:
                count = 30;
                break;
            case 2: 
                if (year % 4 == 0)
                    count = 29;
                else
                    count = 28;
                if ((year % 100 == 0 ) & (year % 400 != 0))
                    count = 28;
 
        }
    return count;
    }
}

Apologies about the long block of code. To me it looks like it's taking the count variable from the 2nd block and importing it into the 1st block.

Although I suppose it is calling the entire method and not the specific count variable. Is that the case? or what am I missing here?

Originally Posted by Norm

Not sure I see what you are asking about. The count variable is only known with the {}s surrounding the code in the countDays method.
The contents of the count variable is returned by the countDays method.

I guess in the first block the countDays from the second block is called. So that is kosher?

If there was a line in the second block that said:

 int x = 3'

That would not be able to be accessed from the first block but methods are ok to call?

I guess I don't understand what information can be passed between blocks. Because the above program is passing some information between the two blocks.