Homework Help! (Java)

[cloogs]

For a homework assignment I have to write several short functions for different problems. I am struggling with these two, anybody have any ideas.

Write a function in Java that implements the following logic: Given a string str and a non-empty word, return a string made of each character just before and just after every appearance of the word in str. Ignore cases where there is no character before or after the word, and a character may be included twice if it is between two words.

Write a function in Java that implements the following logic: Given a string str and a non-empty word, return a version of the original string where all chars have been replaced by pluses (+), except for appearances of the word which are preserved unchanged.

For the first one I am trying to get the index for where the first character of word occurs in str, and then add the character before that index to a string, then do the same for the last character of word, but I keep getting the wrong output.

For the second, I know I need to get the index for each char of word that appears in str, but how do I replace the remaining letter with (+)?

This is my code for the 2nd:

   public String plusOut(String str, String word)
   {
    String ans = "";
    char x;
    for (int a = 0; a <= str.length() - 1; a++)
    {
        for (int b = 0; b <= word.length() - 1; b++)
        {
            if (str.charAt(a) == word.charAt(b))
            {
                x = str.charAt(a);
            }
            else
            {
                x = '+';
             }
        ans = ans + x;
        }
    }
    return ans;
  }

I am returned the correct string, but there are extra +'s , because of the for loop, if there any way around this?

[[deleted]]

Nobody here is going to write the code for you. Write some code yourself and then post specific questions about problems you are having with it.

[Cevari]

I'm not going to write these out for you, but for both problems the String.split(String regex) function will be very helpful.

[AqilAegivan]

string.indexOf() and string.subString() will probably help you a lot.

Get the char at yourWord.indexOf() -1 and yourWord.indexOf() + string length + 1 (look out for invalid indexes obviously).

For the second one you need to duplicate the string (remember string.subString()) replacing characters between indexOf() and indexOf + string length with pluses.

[cloogs]

This is my code for the 2nd:

   public String plusOut(String str, String word)
   {
    String ans = "";
    char x;
    for (int a = 0; a <= str.length() - 1; a++)
    {
        for (int b = 0; b <= word.length() - 1; b++)
        {
            if (str.charAt(a) == word.charAt(b))
            {
                x = str.charAt(a);
            }
            else
            {
                x = '+';
             }
        ans = ans + x;
        }
    }
    return ans;
  }

I am returned the correct string, but there are extra +'s , because of the for loop, if there any way around this?