import 
public 
private
Vector
Serializable
File
Color
extends
boolean
implements

  
extends
public
int
class
someclassname
somesuperclass
implements
File
extends
Class
final

public class test {
   public static void main(String args[]) { 
      String str1="abc";
      String str2="def";
      String str3=str1.concat(str2);

      str1.concat(str2);
      System.out.println(str1);
   }
}

class test {
    public static void main(String args[]) {
        char ch;
        String test2 = "abcd";
        String test = new String("abcd");
        if(test.equals(test2)) {
            if(test == test2)
                ch = test.charAt(0);
            else
                ch = test.charAt(1);	           
        }
        else {
            if(test == test2)
                ch = test.charAt(2);
            else                
                ch = test.charAt(3);
        }
        System.out.println(ch);
    }
}

System.out.println(4 | 3);

class Background implements Runnable {
  int i=0; 

  public int run() {
         while(true) {
                i++;
                System.out.println("i="+i);
            }
     }
}

public class TechnoSample {
    public static void main(String argv[]) {
        TechnoSample sample = new TechnoSample();
        sample.amethod();
    }

    public void amethod() {
        int oi= 012;
        System.out.println(oi);
    }
} // Oct

//Base.java
package Base;

class Base {
    protected void amethod() {
        System.out.println("amethod");
    }
} // Base

package Class1;

public class Class1 extends Base {
    public static void main(String argv[]) {
        Base b = new Base();
        b.amethod();
    }
} // Class1

class TechnoSample {
  public static void main(String args[]) {
    short[] s = {1, -1, 3, 4};
    for (int i = 0; i      switch(s[i]) {
        case 2-1: System.out.print("v ");
        break;
        case 'd'-'a': System.out.print("w ");
        break;
        case 0: System.out.print("x ");
        break;
        case ~0: System.out.print("y ");
        break;
        case 4&5: System.out.print("z ");
        break;
        default: System.out.print("Default ");
      }
    }
  }
}

class TechnoSample {
  public static void main (String args[]) {
    int i = 0;
    int j = 0;
label1:
    while (i++<5) {
label2:
      for (;;) {
label3:
        do {
          System.out.print(i + j);
          switch (i+j++) {
            case 0: continue label3;
            case 1: continue label2;
            case 2: continue label1;
            case 3: break;
            case 4: break label3;
            case 5: break label2;
            case 6: break label1;
            default: break label1;
          }
        } while (++j<5);
      }
    }
  }
}

1. class A {
2.   void m1() {throw new ArithmeticException();}
3.   void m2() {throw new ClassCastException();}
4.   void m3() {throw new IllegalArgumentException();}
5.   void m4() {throw new IndexOutOfBoundsException();}
6.   void m5() {throw new NullPointerException();}
7.   void m6() {throw new SecurityException();}
8. }

class Level1Exception extends Exception {}
class Level2Exception extends Level1Exception {}
class Level3Exception extends Level2Exception {}

class Purple {
  public static void main(String args[]) {
    int a,b,c,d,f,g,x;
    a = b = c = d = f = g = 0;
    x = 3;
    try {
      try {
        switch (x) {
          case 1: throw new Level1Exception();
          case 2: throw new Level2Exception();
          case 3: throw new Level3Exception();
        }
        a++;
      }
      catch (Level2Exception e) {b++;}
      finally{c++;}
    }
    catch (Level1Exception e) { d++;}
    catch (Exception e) {f++;}
    finally {g++;}
    System.out.print(a+","+b+","+c+","+d+","+f+","+g);
  }
}

class A {

  public static void main (String args[]) {
    int h = 0, i = 0, j = 0, k = 0;

label1:
    for (;;) {
      h++;

label2:
      do {
        i++;
        k = h + i + j;

        switch (k) {
          default: break label1;
          case 1: continue label1;
          case 2: break;
          case 3: break label2;
          case 4: continue label2;
          case 5: continue label1;
        }
      } while (++j<5);
    }
    System.out.println(h + "," + i + "," + j);
  }
}

public 
protected 
private

1: public class Q1 extends Thread
2: {
3:    public void run()
4:    {
5:       System.out.println("Before start method");
6:       this.stop();
7:       System.out.println("After stop method");
8:    }
9:
10:   public static void main(String[] args)
11:   {
12:      Q1 a = new Q1();
13:      a.start();
14:   }
15: }

1     class Test
2     {
3          void show()
4          {
5              System.out.println("non-static method in Test");
6          }
7     }
8     public class Q3 extends Test
9     {
10       static void show()
11       {
12           System.out.println("Overridden non-static method in Q3");
13       }
14 
15       public static void main(String[] args)
16       {
17           Q3 a = new Q3();
18       }
19    }

1    if( new Boolean("true") == new Boolean("true"))
2        System.out.println("True");
3    else
4        System.out.println("False");

public class Rand {
    public static void main(String argv[]) {
        int iRand;
        iRand = Math.random();
        System.out.println(iRand);
    }
} // Rand

1:    Double a = new Double(Double.NaN);
2:    Double b = new Double(Double.NaN);
3:
4:    if( Double.NaN == Double.NaN )
5:       System.out.println("True");
6:    else
7:       System.out.println("False");
8:
9:    if( a.equals(b) )
10:      System.out.println("True");
11:   else
12:      System.out.println("False");

1     public class Q11
2     {
3         static String str1 = "main method with String[] args";
4         static String str2 = "main method with int[] args";
5 
6         public static void main(String[] args)
7         {
8             System.out.println(str1);
9         }
10 
11        public static void main(int[] args)
12        {
13            System.out.println(str2);
14        }
15     }

1 int i = 16;
2 int j = 17;
3
4 System.out.println("i >> 1  =  " + (i >> 1));
5 System.out.println("j >> 1  =  " + (j >> 1));

1  int i = 45678;
2  int j = ~i;
3
4  System.out.println(j);

1  void infiniteLoop()
2  {
3      byte b = 1;
4
5      while ( ++b > 0 )
6          ;
7      System.out.println("Welcome to Java");
8  }

class A {}
class B extends A {}

public class C 
{
	public static void main(String[] args)
	{
		A[] arrA;
		B[] arrB;

		arrA = new A[10];
		arrB = new B[20];

		arrA = arrB; // (1)
		arrB = (B[]) arrA; // (2)

		arrA = new A[10];
		arrB = (B[]) arrA; // (3)
	}
}

public class Boxes{
    String sValue;

    Boxes(String sValue){
    this.sValue=sValue;
    }
    
    public String getValue(){
    return sValue;
    }

    public boolean equals(Object o){
    String s = (String) o;
    if (sValue.equals(s) ){
        return true;
    }else{
        return false;
    }


    }

    public int hashCode(){
    return sValue.hashCode();

    }
}

public class TechnoExample
{
    int xyz = 22;
    ...

    public void static main(String junkArgs[])
    {
        ...
    }
}