why will this compile coreectly

[Chad McAtee]

Hey folks,

I am new to this site as well as java programming. Dont understand the logic behind while this compiles correctly.

public static void main(String[] args) {

        int weight = 10, thePrice;

        if(true) 
            thePrice = 1000;
        
        System.out.println("The price is = " + thePrice);

also with the if(true) statement what condition is being tested as being true?

However this compiles with the error variable not initialized

        int weight = 10, thePrice;

        if(weight > 10) thePrice = 1000; 
                   
        System.out.println("The price is = " + thePrice);

[Markas Korotkovas]

it makes it a lot easier to read your post if you surround your code by {code} brackets. But anyway in the first snippet you are declaring 2 int variables weight and thePrice. You are also initializing the weight with a value of 10. thePrice is not initialized at this point. The condition if(true) is alway true, so the next statement right after it will always execute and initialize thePrice with a value of 1000. By changing the condition in the second snippet the statement of

thePrice=1000;

never executes and when you get to the line that prints the result thePrice variable is never initialized and therefore will result in an error.

[Christophe Verré]

Welcome to the ranch Chad.

The code brackets Markas is talking about are explained here. I've added them for you this time.

[Anbarasu Aladiyan]

Below are some small snippets and behavior of compiler:

boolean a = true;
if(a) thePrice = 1000;   
System.out.println("The price is = " + thePrice);

Above code causes compiler error because value of 'a' can be changed

if(true) thePrice = 1000;   
System.out.println("The price is = " + thePrice);

Above cod compiles fine because if condition cannot be false

final boolean a = true;
if(true) thePrice = 1000;   
System.out.println("The price is = " + thePrice);

Above cod compiles fine because value of a cannot be changed (since a is final)

boolean a = true;
if(a) thePrice = 1000;  
else theprice=500;
System.out.println("The price is = " + thePrice);

Above cod compiles fine because thePrice variable will be initialized to at least some value.

So compiler expects a constant (because it should not get changed by any other codes) to make sure conditions succeeds always.

[Anbarasu Aladiyan]

and Welcome to javaranch

[Jatin Vij]

@<Anbarasu Aladiyan> That's an awesome explaination! Helped me brush up my concepts even though I've been writing in Java for some time now.
Good job!