Boolean that contains "bab"

Recursion should be considered as two parts.

1) The main case. This is a trivial case that can be easily determined. What you have is a good start to the base case. 1) String less than 3? Then return false. 2) The line starts with "bab" and then returns true.

2) Recursive case. This breaks down the problem into more subtle problems, and if you separate them reliably enough, you will have a base case.

@Logiraptro has a good example of simple recursion.

public static boolean hasBAB(String str) {
  if (str.length() < 3) return false;
  if (str.substring(0,3).equals("bab"))
    return true;
  else
    return hasBAB(str.substring(1));
}

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public static boolean hasBAB(String str) {
      String searchString = "bab";

      // Base cases
      if (str.length() < searchString.length()) 
          return false;

      if (str.length() == searchString.length())
      {
          if (str.equals(searchString))
          {
              return true;
          }
          return false;
      }

      int halfWay = str.length()/2;

      // Now check for the search string over the "break"
      for (int i = 0; i < searchString.length(); i++)
      {
          int startIndex = halfWay - 1 - i;
          int endIndex = startIndex + 3;
          if (startIndex >= 0)
          {
              String substring = str.substring(startIndex, endIndex);
              if (substring.equals(searchString))
              {
                  return true;
              }
          }
      }

     // Recursive Cases 
     //  We did find the search string over the break,so break the string into two equal(ish) pieces and check those 
     if(hasBAB(str.substring(0,halfWay -1)))
         return true;

     if(hasBAB(str.substring(halfWay, str.length())))
         return true;

     return false;
}