I can only print string literals

I'm writing a class to make a random password, but for some reason I can only print string literals in the main method. Can anyone tell me why?

Code:

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public class RandomPassword
{
        /* main method, only used for testing methods */
        public static void main(String[] args)
        {
                System.out.print(RandomPassword.fixLast("this_"));
        }

        /* returns random char alpha (caps or no caps) or underscore '_'
        *this will temporrily return char 'a', waiting for ***'s method */
        public static char randomChar()
        {
                return 'a';
        }
       
        /*fixLast, this will test to make sure that the last character of password is not '_'
        *if it is it will replace the last character with a random char (by calling randomChar) */
        public static String fixLast(String pass)
        {
                //isolates the last char of the password
                char lastChar = (pass.charAt(pass.length()-1));               
               
                //test if lastChar meets the required range.
                while(('a' <= lastChar && 'z' >= lastChar) || ('A' <=lastChar && 90 >= 'Z'))
                {
                        pass = pass.substring(0, pass.length()-1) + RandomPassword.randomChar();
                        lastChar = (pass.charAt(pass.length()-1));
                }
                return pass;
        }
               


}

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Quote:

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Originally Posted by leeavital

I'm writing a class to make a random password, but for some reason I can only print string literals in the main method. Can anyone tell me why?

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Your code returns a String, so it outputs a String, I'm confused to your question. What are you trying to output, but are unable to? - your code doesn't reflect this.

Edit:
After running your code and entering an infinite loop, I checked your code. What is it that you are trying to do with your loop in the fixLast method? Currently, it loops while the character is in the range (and it doesn't properly check the range).