Class String

With a Java development environment such as such as Borland JBuilder or Symantec Café the documentation is on line (push F1). If you downloaded the JDK from Sun Microsystems, look on your hard disk, in someplace like C:\jdk1.2.2\docs\index.html. Here is a short version of the documentation for String. There are more methods than in this list.

    // Constructors
    public String(); 
    public String(String  value); 

    // Methods
    public char charAt(int  index);
    public String concat(String  str); 
    public boolean endsWith(String  suffix); 
    public boolean equals(Object  anObject); 
    public boolean equalsIgnoreCase(String  anotherString); 
    public int indexOf(int  ch); 
    public int indexOf(String  str); 
                       
    public int length(); 
    public boolean startsWith(String  prefix); 
    public String substring(int  beginIndex, int endIndex); 
    public String toLowerCase(); 
    public String toUpperCase(); 
    public String trim();

The documentation first lists constructors. Then it says how to call the methods. For example,

    public String concat(String  str); 
    --+--- --+---  --+--  ----+----
      |      |       |        |
      |      |       |        |
      |      |       |        +---- says that there must be a String reference parameter
      |      |       |
      |      |       +----- the name of the method
      |      |
      |      +----- the method returns a reference to a new String object
      |
      +----- anywhere you have a String object, you can use this method

QUESTION 7:

Is the following code correct?

String first = "Kublai" ;
String last  = " Khan" ;
String name  = first.concat( last );

You don't have to know what this does; just look at the documentation and see if the types of all the parts are correct.

Click Here after you have answered the question