Question

Write a recursive method to remove all special characters and spaces from a sentence without using replaceAll

Then write a recursive method to check if the sentence is a palindrome after removing all special characters and spaces.

Answer 1

To remove special characters and spaces from a sentence recursively, create a method that checks each character and concatenates the non-special characters. To check if the resulting sentence is a palindrome, create a method that compares the first and last characters recursively.

Step-by-step explanation:

To remove all special characters and spaces from a sentence recursively without using replaceAll, you can follow these steps:

1. Create a recursive method that takes in a sentence as a parameter.
2. If the sentence is empty, return an empty string.
3. If the first character of the sentence is a special character or space, recursively call the method with the remaining characters of the sentence.
4. If the first character is not a special character or space, concatenate it with the result of recursively calling the method with the remaining characters of the sentence.

To check if the sentence is a palindrome after removing all special characters and spaces, you can follow these steps:

1. Create a recursive method that takes in a sentence as a parameter.
2. If the sentence is empty or has only one character, return true.
3. If the first and last characters of the sentence are equal, recursively call the method with the sentence excluding the first and last characters.
4. If the first and last characters are not equal, return false.