Could you please help me to find whats wrong in the code

[muruga dhanapal]

Could you please help me to know whats wrong in the code

public class SImple {

	/**
	 * @param args level
	 * 
	 */
	public static void main(String args[]) {
		String s = "level";
		isPalindrome(s);
	}
	public static boolean isPalindrome(String s) {
		String comp = s;
		boolean flag = false;
		int j = 0;
		for(int i =0; i< s.length(); i++) {
			System.out.println(s.charAt(i));
			for (j = comp.length()-1; j > 0; j -- ){
				System.out.println("After comparing" + comp.charAt(j));
				if(s.charAt(i) != comp.charAt(j) ) {
					flag = false;					
				}
				break;
		}
			
			
	}
		
		if(!flag){
			System.out.println("Not palindrome :" + flag);
		return flag;
		} else {
			System.out.println("Its an Palindrome :" + flag);
			return flag;
			
		}
}
}

Could you please help me whats wrong in the code am trying to check a string is palindrome or not?

The second for loop J is not iterating

[Saif Asif]

Hello muruga dhanapal ,

Why are you using two loops to check for the palindrome nature of the String. I believe a single loop will be enough to accomplish your task as below

public static boolean isPalindrome(String s) {  
		String comp = s;  
		boolean flag = false;  
		int j = 0;  
		for(int i = 0 ; i < s.length() ; i++) {
			if( comp.charAt( i ) != comp.charAt( (s.length()-1) - i ) ){
				flag = false;
				break;
			}
			else{
				flag = true ;
			}
		}  

		if(!flag){  
			System.out.println("Not palindrome :" + flag);  
			return flag;  
		} else {  
			System.out.println("Its an Palindrome :" + flag);  
			return flag;  

		}  
	}

[Winston Gutkowski]

Saif Asif wrote:I believe a single loop will be enough to accomplish your task as below...

Saif,

Please don't hand out ready-made solutions. I'm sure you were just trying to help, but we much prefer people to work things out for themselves here.
You also run the risk of misinforming, or providing solutions that are less than optimal - and yours is.

Winston

[Saif Asif]

Winston Gutkowski ,

or providing solutions that are less than optimal - and yours is.

Please specify where you feel the code is not optimal.

[Winston Gutkowski]

Saif Asif wrote:Please specify where you feel the code is not optimal.

All right, since you ask:
1. You don't need to keep a boolean.
2. You don't need to keep another String.
3. You don't need to traverse the entire String.
4. You don't need to call length() on each iteration.
5. Your println() statements belong outside the method (that, admittedly, is arguable; but I stick by it).
6. You never use the variable 'j'.

Winston

[Saif Asif]

public static boolean isPalindrome(String stringToCompage) {
		int halfway = (stringToCompage.length() - 1 ) / 2 ;
		for(int i = 0 ; i <= halfway ; i++) {
			if( stringToCompage.charAt( i ) != stringToCompage.charAt( (stringToCompage.length()-1) - i ) ){
				System.out.println("Not palindrome :" + false );  
				return false ;
			}
		}
		return true ;
		
	}

You do not have to doubt my coding conventions . I was merely trying to explain him the problem by his own code sample that he had provided , since it would have been much easier for him to understand his own code rather than to read an entirely different code algorithm. And I also have a firm believe on the fact that there are multiple ways to accomplish a coding task. Not all may be optimal , true , but most are . One should be open to opinions from different programmers.

[Winston Gutkowski]

Saif Asif wrote:the fact that there are multiple ways to accomplish a coding task.

Very true.

Not all may be optimal , true , but most are.

Not true. Only one is likely to be optimal, because that's what 'optimal' means - although there may be different ways of writing it.

One should be open to opinions from different programmers.

Opinons are not the issue here. The fact is that you have handed out a solution, when simple advice would have sufficed. It also goes against the ethos of this site, which is to provide help, not code; so please DontBeACodeMill (←click).

Winston

[Saif Asif]

Got it :-) I will take care next time :-)