我想問 : 什麼是 Java, 和 Java 有什麼用途 ?

elia﹐Java 是一種 programming 的 language。 平時不常用到﹐但有很多人靠他 "搵兩餐"。

anyone know how to stdout a string in reverse without using any pointer?

是不是這個 ?

Below is the syntax highlighted version of StdOut.java from §1.5 Input and Output.

/*************************************************************************
*  Compilation:  javac StdOut.java
*  Execution:    java StdOut
*
*  Writes data of various types to standard output.
*
*************************************************************************/


public class StdOut {

    // can't instantiate
    private StdOut() { }


    public static void close() { System.out.close(); }

    public static void println()          { System.out.println();  }
    public static void println(Object x)  { System.out.println(x); }
    public static void println(boolean x) { System.out.println(x); }
    public static void println(char x)    { System.out.println(x); }
    public static void println(double x)  { System.out.println(x); }
    public static void println(float x)   { System.out.println(x); }
    public static void println(int x)     { System.out.println(x); }
    public static void println(long x)    { System.out.println(x); }

    public static void print(Object x)    { System.out.print(x);   }
    public static void print(boolean x)   { System.out.print(x);   }
    public static void print(char x)      { System.out.print(x);   }
    public static void print(double x)    { System.out.print(x);   }
    public static void print(float x)     { System.out.print(x);   }
    public static void print(int x)       { System.out.print(x);   }
    public static void print(long x)      { System.out.print(x);   }

    public static void printf(String format, Object... args) {
        System.out.printf(format, args);
    }

    // This method is just here to test the class
    public static void main (String[] args) {

        // write to stdout
        System.out.println("Test");
        System.out.println(17);
        System.out.println(true);
        System.out.printf("%.6f\n", 1.0/7.0);
    }

Don't understand what you mean by "stdout a string in reverse".

To stdout a string, we do:


What is "in reverse"?

Unlike C++, there is no "pointer" concept in Java.  Everything is managed by the JVM (Java Virtual Machine).  When you declare a new object, the memory allocation is done by the VM for you.

To reverse a string and output it, you can use java.lang.StringBuffer.  See the following code snippet:

import java.lang.StringBuffer;

public class HelloWorld
{
  public static void main (String args[])
  {
    StringBuffer strBuf = new StringBuffer("Hello World");
    System.out.println (strBuf.reverse().toString());
  }
}

Good job pufferfish00!!  I was confused at one point what vvheme was asking, but now I got it!  Print the string in the reverse order!    I think I should work harder on my english level.. hee!

Java Class Library 有好多現成method

what is java api???

其實我喺市面上常見到J2EE、J2SE等等......
其實係有咩分別架？你地講哥個軟件係點樣安裝架？