Code from recitation 6

1. Take a String, and make just the first letter capital.

     Capital.java 

  1  public class Capital {
  2  
  3      public static void main(String[] args) {
  4          String x = "abcdefgh";
  5  
  6          String y = x.substring(0, 1).toUpperCase();
  7          String z = x.substring(1, x.length());
  8          System.out.println(y + z);
  9      }
 10  }

Abcdefgh

2. See if a particular String belongs to an array (note that we haven't gotten to arrays yet. But we will).

     InList.java 

  1  public class InList {
  2      public static void main(String[] args) {
  3          String[] a = { "a", "aa", "aaa" };
  4  
  5          String x = "asdfjeoi";
  6          boolean in = false;
  7          for (int i=0; i<a.length; i++) {
  8              String y = a[i];
  9              if (x.equals(y)) {
 10                  in = true;
 11                  break;
 12              }
 13          }
 14          if (in == true) {
 15              System.out.println("x is in a");
 16          }
 17          else {
 18              System.out.println("x is NOT in a");
 19          }
 20      }
 21  }

x is NOT in a

3. Go through the words in a sentence and count how many letters are in each:

     LetterCount.java 

  1  public class LetterCount {
  2      public static void main(String[] args) {
  3          String x = " words in a sentence ";
  4  
  5          for (int i=0; i<x.length(); i++) {
  6  
  7              if (x.charAt(i) == ' ') {
  8                  for (int j=i+1; j<x.length(); j++) {
  9                      if (x.charAt(j) == ' ') {
 10                          int length = j - i - 1;
 11                          String word = x.substring(i, j);
 12                          System.out.println(word);
 13                          System.out.println(length);
 14                          break;
 15                      }
 16                  }
 17              }
 18          }
 19      }
 20  }

 words
5
 in
2
 a
1
 sentence
8

Note the extra spaces around the word in order to make our algorithm work. We could also have written:

  1  String x = "words in a sentence";
  2  x = " " + x + " ";