Thread: Simple but Strange situation in my Java Code.

Hi, still not getting the if() condition to be true.

public String isPalindrome(String word) {
		StringBuilder builder = new StringBuilder(word);
		String reversed = builder.reverse().toString();
		String s = new String();
		if(reversed.equalsIgnoreCase(word)){
		 s = "Word " + word +  " is a palindrome!";
		}
		return  s;
   }

the mystery is in this lines of code:

if(reversed.equalsIgnoreCase(word)){
		 s = "Word " + word +  " is a palindrome!";
		}

I tested with the word :"evitative" the if() condition is false even though reversed and word are the same.

I tested with the word :"evitative" the if() condition is false even though reversed and word are the same.

How do you know it evaluates to false? The code you posted does not contain any way to test this...it is always best to post an SSCCE that shows all the code necessary to reproduce the problem

I stated clearly that the statement in the if() condition was NEVER executed.

You did not state clearly how you know this. Did you add println's in there to see? Are you relying on the string returned from the method? Are you relying on a debugger? Whichever way, if you read post #4:

it provided the correct result

Suggesting the problem may be in the manner in which you are testing/calling the code, without which we can only guess what the problem is.

And how are you calling the method? When you run that code, what does it print? More information is often better (removes the guesswork) - here's an example of an SSCCE, using your code above plus a main method to call isPalindrome:

public class Test {
 
	public static void main(String[] args){
		System.out.println(isPalindrome("evitative"));
	}
 
	public static String isPalindrome(String word) {
 
		String s = new String("word is NOT a palindrome");
 
		StringBuilder builder = new StringBuilder(word);
		String reversed = builder.reverse().toString();
		System.out.println(reversed + "\n");
		System.out.println(word + "\n");
		System.out.println(reversed.equalsIgnoreCase(word) + "\n");
 
		if(reversed.equalsIgnoreCase(word)){
			s = "Word " + word +  " is a palindrome!";
		}
		return  s;
	}
}

Prints:

evitative
 
evitative
 
true
 
Word evitative is a palindrome!

Originally Posted by help_desk

Everything displays as yours except the if() condition being false.

Post exactly what you ran, and the result. If you ran the code I posted above, the output should be identical. Without knowing what you ran, as well as the context, we are only left to guess.

IF there is a way to post a full project here, kindly let me know.

I asked for an SSCCE that demonstrates the problem - see my signature for a full description of what that is, posting the full project will result in a lot of code unrelated to the problem (and code many don't want to wade through). Creating an SSCCE is not just for our benefit but for yours, because it is an essential technique in debugging (and often one can diagnose the problem simply in the process of creating one)

This being said, without seeing how you are calling the method (with what input) we can't really help you because - as the SSCCE I posted above demonstrates - the problem does not appear to be contained within the code posted.

steps:
1. user enters the following on request:

"isPalindrome evitative"

2. this string is passed into the commands interprete method

3. In the interprete method, the string is split into two parts: "isPalindrome" and "evitative"
a. the first part "isPalindrome" is passed into a find(operand) method to check that the
command has any such operand.
b.IF that is true, then it goes through a switch loop to call the appropriate method for the operand, in this case, the IsPalindrome object is called.
c. and in the IsPalindrome class is the isPalindrome method that finally does the computation.

public static void main(String[] args) {
		System.out.println("Enter a word please : \n");
		/*
		* I tested with the word evitative
		*/
		Scanner st = new Scanner(System.in);
		String word = st.nextLine();
		String result = commands.interprete(word);
		System.out.println(result);
		}
 
 
INTERPRETE METHODS AND HELPER METHODS
 
 
public String getOperands(String[] lineOperands){
	StringBuilder operands = new StringBuilder("");
	String [] lineParts = new String[lineOperands.length-1];
 
	for(int i = 1, j = 0; i<=lineParts.length; ++i) 
		lineParts[j++] = lineOperands[i];
 
		for(String operand : lineParts){
			operands.append(operand);
			operands.append(" ");
		}
		return operands.toString();
 
	}
 
 
	public boolean find(String operator){
			boolean flag = false;
			for(Command command : commandArray){
				if(command.getStr().equals(operator)){
				  flag = true;
				  break;
				}
 
			}
 
			return flag;
		}
 
 
public String interprete(String s){
 
		String[] lineParts = s.split("\\s+");
		String operator = lineParts[0];
		String operatorCase = operator.toLowerCase(); 
		if(find(operator.toLowerCase())){ 
			switch(operatorCase){
 
 
 
 
			case "capitals" : 	s = getOperands(lineParts);
								Capitals capital = new Capitals();
							  	s = capital.makeCapital(s);
							  	break;
 
			case "ispalindrome": s = getOperands(lineParts);
								 IsPalindrome palindrome = new IsPalindrome();
								 s = palindrome.isPalindrome(s);
								 break;
 
 
 
			}
		} else System.out.println("Command " + operator + " is unknown!");
 
		return s;
 
	}
 
 
 
	isPalindrome(String word){
	String s = new String("Word is NOT palindrome");
	StringBuilder builder = new StringBuilder(word);
			String reversed = builder.reverse().toString();
 
			System.out.println(reversed + "\n");
			System.out.println(word + "\n");
			System.out.println(reversed.equalsIgnoreCase(word) + "\n");
 
			if(word.equals(reversed)){
			 s = "Word " + parameters +  " is a palindrome!";
			}
			return  s;
 
	}

Both Greg and I posted SSCCE's that demonstrate the method (as posted) works as expected with the test input. So my advice would be to backup and have a hard look at the input for this method...is the input to the isPalindrome method what you expect (you can test this with a few println's)? Are you sure the data that is parsed/returned by getOperands is what you expect/correct? (hint, the answer to these questions is no)

I don't need the full project - the issue is contained within the code you posted (but not an easy thing to spot). Like I said, inspect that you are passing what you expect the isPalindrome method - for instance, if you enter "isPalindrome civic" does the parameter to isPalindrome equal 'civic'? If not, back up in your code to see how this may have occurred