Can anyone explain this logic?

[hotsauce]

This part of the program takes a string and print each letter on a single line, while speaking the string backwards.


To termination the For loop in the printBackwards method it's n>= 0. I originally thought it would be n==0, but using n==0 the compiler just terminates the program. I was only able to get it to work through trial and error (n>=0).

	

public static void main(String[] args) {
		
		String word = "Backpack";
		
		printBackwards(word);

	}

public static void printBackwards (String s){
	
		for ( int n = length(s) - 1; n >= 0; n--){
			System.out.println(s.charAt(n));
			
		}
	}

Output:

kcapkcaB

[Eranga]

What will print when you compile and run this code?

[Norm]

Add a println to show the values of the variable n as the loop executes.

[Junky]

I originally thought it would be n==0

If you used that as the condition it means that the loop would only execute if n IS zero. There are 3 possibilities.

Initial value of n is zero. Condition is true. Execute loop. Change value of n. Condition is false. Exit. Loop only executes once which is pointless.

Initial value of n is zero. Condition is true. Execute loop. Never change value of n. Condition is true. Endless loop. Not very useful either.

Initial value of n is not zero. Condition is false. Never executes loop. Yet again a pointless loop.

[Eranga]

No response from OP for a long time.

[hotsauce]

No, I'm still here. Didn't have internet for awhile.

Thanks for the explanation, it really helped.