CodeLab Solution 20860




CS125 CodeLab Solutions

CodeLab Solution 20860

Write a recursive, string -valued method , reverse, that accepts a string and returns a new string consisting of the original string in reverse. For example, calling reverse with the string goodbye returns the string eybdoog.

Reversing a string involves:

Nothing if the string is empty or has only 1 character (reversing a single character string does not change anything)
Otherwise concatenate the last character with the result of reversing the string consisting of the second through the next-to-last character , followed by the first character . In the above example, you would concatenate the ‘e’ (last character of goodbye) with the result of calling reverse on oodby (the string from the second character to the next-to-last), with the ‘g’ (first character ).

[cc lang=”JAVA”] public static String reverse (String str) {
return str.isEmpty()? “”: reverse(str.substring(1)) + str.charAt(0);
}
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