Write a java code to print following pattern

(a)
(a+b)
(a+b+c)
(a+b+c+d)


Solution:

//PrintABCD.java
class PrintABCD
{
public static void main(String abc[])
{
for(int i=1;i<10;i++) // increase count 10 to 27 to print till "z"
        {          
            String strChars="";  
            int alphabet=97;                          //ASCII value of A = 65 and a=97
            for(int j=1;j<=i;j++)
              {
                strChars=strChars+(char)alphabet + " + ";
                alphabet++;
              } 
          System.out.println("(" + strChars.substring(0,strChars.length()-3) + ")");
         }
     }
}

Write a java code to print following pattern

AAAA
   AAA
      AA
         A
         A
         AB
         ABC
         ABCD

Solution:
//PrintABCD.java
class PrintABCD
{
     public static void main(String abc[])
     {
        printAAAA();
        printABCD();
     }
    
    static void printABCD()
    {
        for(int i=1;i<5;i++)
        {          
            for(int k=3;k>0;k--)
            {
                    System.out.print(" ");
            }      
           
            int alphabet=65;                          //ASCII value of A
            for(int j=1;j<=i;j++)
              {
                System.out.print((char)alphabet);
                alphabet++;
              }
          System.out.println();
         }
}

    static void printAAAA()
    {
        int alphabet=65;                          //ASCII value of A
        for(int i=4;i>0;i--)
        {      
            for(int k=4;k>i;k--)
            {
                    System.out.print(" ");
            }   
                for(int j=1;j<=i;j++)
                {
                    System.out.print((char)alphabet);
                }
                System.out.println();
         }
    }
}

Write a Java code to print following pattern

A
BC
DEF
GHIJ

Solution:
 
//PrintABCD.java
class PrintABCD
{
     public static void main(String abc[])
     {
        int alphabet=65;                          //ASCII value of A
        for(int i=1;i<5;i++)
        {           
            for(int j=1;j<=i;j++)
              {
                System.out.print((char)alphabet);
                alphabet++;
              }
          System.out.println();
         }
     }
}

Write a java code to print following pattern

 

J
JA
JAV
JAVA
JAVAJ
JAVAJ2
JAVAJ2E
JAVAJ2EE

Solution:

class PrintJava
{
public static void main(String[] args)
{
char[] arrChar={'J','A','V','A','J','2','E','E'};
for(int i=0;i<=8;i++)
{
for(int j=0;j<i;j++)
{
System.out.print(arrChar[j]);
}
System.out.println();
}
}
}

Write a java code to print following pattern

1
23
456

Solution:

class printPattern
{
     public static void main(String abc[])
     {
        int counter=1;    
        for(int i=1;i<4;i++)
        {                    
            for(int j=1;j<=i;j++)
              {
                System.out.print(counter);
                counter++;
              }
              System.out.println();
         }
     }
}

Write a java code to print following pattern

A
BB
CCC
DDDD


Solution:

class printABCD
{
     public static void main(String abc[])
     {
        int alphabet=65;                          //ASCII value of A
        for(int i=1;i<5;i++)
        {
            for(int j=1;j<=i;j++)
              {
                System.out.print((char)alphabet);
              }
                System.out.println();
                alphabet++;
         }
     }
}

Is it possible to overload main() method of java. If yes, explain with example.

Ans:
Yes, it is possible to overload main() method in java. You can have more than one main method but with different argument list.
A simple example of overloading main method:

//Test.java
class Test
{
public static void main(String abc[])
{
System.out.println("In Main method");
main(10);
}
static void main(int num)
{
System.out.println("Overloaded main method : prints number :" + num);
}
}