Java Recursive Palindrome Check in Java: An Efficient Solution

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To create a recursive function in Java that checks if a string is a palindrome, start by defining the function with two parameters representing the indices of the first and last characters of the string. The function should compare these characters; if they are not the same, it returns false. If they are the same, the function checks if it has reached the center of the string. This occurs when the two indices are equal (for odd-length palindromes) or when the second index is one greater than the first (for even-length palindromes). If either condition is met, the function returns true. If not, it recursively calls itself with updated indices (incrementing the first index and decrementing the second) until the check is complete. This approach effectively verifies if the string reads the same forwards and backwards.
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Would you tell me how to write a test_function to check a given string whether it is a palindrome or not in Java recursively ?
Thank you,

-Pattielli
 
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The initial condition of the recursion is that the function is checking the first and last characters to see if they're the same. In other words, the recursive function is called with two arguments: (0, string.length() - 1). I will call those arguments a and b.

The function checks the two characters at the positions (a and b) given by the arguments. If they are not the same, the function return false.

If they are the same, the function first checks to see if it has met the condition to complete the check. If a and b are the same number, the recursion has reached the center of an odd-length palindrome. If b is one greater than a, then the recursion has reached the center of an even-length palindrome. If either of these conditions is true, the function returns true. If these conditions are not true, the check is not complete yet, and the function calls itself with arguments (a+1, b-1), and returns whatever result that call returns.

- Warren
 
Many Thanks to Warren, I understand and made my program work fine as what you told me, Thanks a lot,

- Pattielli
 
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