How to capitalize the first and last letters of every word in a string in java

Question

How to capitalize the first and last letters of every word in a string

i have done it this way -

    String cap = "";
    for (int i = 0; i < sent.length() - 1; i++)
    {
        if (sent.charAt(i + 1) == ' ')
        {
            cap += Character.toUpperCase(sent.charAt(i)) + " " + Character.toUpperCase(sent.charAt(i + 2));
            i += 2;
        }
        else
            cap += sent.charAt(i);
    }
    cap += Character.toUpperCase(sent.charAt(sent.length() - 1));
    System.out.print (cap);

It does not work when the first word is of more than single character

Please use simple functions as i am a beginner

Answer 1

Using apache commons lang library it becomes very easy to do:

    String testString = "this string is needed to be 1st and 2nd letter-uppercased for each word";

    testString = WordUtils.capitalize(testString);
    testString = StringUtils.reverse(testString);
    testString = WordUtils.capitalize(testString);
    testString = StringUtils.reverse(testString);
    System.out.println(testString);

ThiS StrinG IS NeedeD TO BE 1sT AnD 2nD Letter-uppercaseD FoR EacH WorD

Answer 2

You should rather split your String with a whitespace as character separator, then for each token apply toUpperCase() on the first and the last character and create a new String as result.

Very simple sample :

  String cap = "";
  String sent = "hello  world. again.";

  String[] token = sent.split("\\s+|\\.$");

  for (String currentToken : token){
      String firstChar = String.valueOf(Character.toUpperCase(currentToken.charAt(0)));
      String between = currentToken.substring(1, currentToken.length()-1);
      String LastChar = String.valueOf(Character.toUpperCase(currentToken.charAt(currentToken.length()-1)));
      if (!cap.equals("")){
        cap += " ";
      }
      cap += firstChar+between+LastChar; 
  }

Of course you should favor the use of StringBuilder over String as you perform many concatenations.

Output result : HellO World. AgaiN