Help with initialize int variable without assigning a number?

[equal]

Hello! I wonder if it is possible to initialize a variable without giving it an value?
The part of my program I'm having trouble with:

//*The program will ask for 10 ints, when 10 ints have been taken in from 
//input the software will print the 2 biggest and the 2 smallest int. I've got it
//to work if i assign hels1,hels2,helm1,helm2 with a value. But if I do that
//and the lowest number taken from input is higher the value given to the
// variable the software looses its function...  Does anyone have any ideas? //Thanks in advace!


for (int antHel = 0, hels1, hels2, helm1, helm2; antHel <= 10; antHel++ )  {    
	    System.out.println("Skriv in ett heltal: ");
	    
	    //check the variable that is given from scanner and checks if to replace..
		int i = sc.nextInt();
		if (i >= hels1)
			hels1 = i;
			
			else if(i < hels1 && i <= hels2)
				hels2 = i;
		
			
			else if(i >= helm1)
			helm1 = i;
		
		else if(i <= helm2)
			helm2 = i;
		
	

	System.out.println(hels1);
	System.out.println(hels2);
	System.out.println(helm1);
	System.out.println(helm2);
	
			
			
	
	}
			
		
	
	
	}
	

}

[RichWade]

One way to handle the initialization is to use a "first time" initializer. Basically when you get the first number initialize your min and max variables to equal the first number entered. Here is an example:

        int iteration, i, min, max;
        Boolean isFirstTime = true;
        Boolean isInputGood = true;
        Scanner in = new Scanner(System.in);

        i = min = max = 0;
        iteration = 0;
        while (iteration < 10)
        {
            System.out.print("Enter a number: ");
            try
            {
                i = in.nextInt();
                isInputGood = true;
            }
            catch (Exception e)
            {
                System.out.println("EXCEPTION! " + e.toString());
                isInputGood = false;
                // or whatever exception handling you want . . .
            }

            if (isInputGood)
            {
                iteration++;
                
                if (isFirstTime)
                {
                    min = max = i;
                    isFirstTime = false;
                }
                else
                {
                    if (i < min) min = i;
                    if (i > max) max = i;
                }
            }
        }

        System.out.println("Minimum = " + Integer.toString(min));
        System.out.println("Maximum = " + Integer.toString(max));

[couling]

In short no. Initialising a variable means setting its value. There is no difference between the two.

Java will not let you read from a variable if it can not proove that its value has been set. Otherwise there would be a risk that it would simply read whatever the last program left in memory.

Java's ability to check that you've set a variable is quite unintelligent. But predicting when java will or wont accept a variable as being set is still a little tricky though. But avoid setting it inside a loop.

Looking briefly at your code:
If you want to avoid initialising the variables to 0 (allowing negative numbers as input) then you should use a boolean variable as an indicator.

eg:

int x = 0; // yes the =0 is needed!
boolean xSet = false;
for (int i=0; i<10; i++) {
    int y = readValue();
    if (!xSet) {
        x = y;
        xSet = true;
    }
    else if (x > y) {
        x = y;
    }
    // ....
}

Hope this helps

[KevinWorkman]

Another common practice is to initialize your minimum variable to be Integer.MAX_VALUE and your maximum variable to be Integer.MIN_VALUE. That way you know they'll be set the first time around.

Or you could do the "first time" initialization. You don't even need any pesky booleans. Just do a scan before the loop to do the setting and loop one less time.