Java program structure

Structure of a java program is the standard format released by Language developer to the Industry programmer.

Sun Micro System has prescribed the following structure for the java programmers for developing java application.

• A package is a collection of classes, interfaces and sub-packages. A sub package contains collection of classes, interfaces and sub-sub packages etc. java.lang.*; package is imported by default and this package is known as default package.
• Class is keyword used for developing user defined data type and every java program must start with a concept of class.
• "ClassName" represent a java valid variable name treated as a name of the class each and every class name in java is treated as user-defined data type.
• Data member represents either instance or static they will be selected based on the name of the class.
• User-defined methods represents either instance or static they are meant for performing the operations either once or each and every time.
• Each and every java program starts execution from the main() method. And hence main() method is known as program driver.
• Since main() method of java is not returning any value and hence its return type must be void.
• Since main() method of java executes only once throughout the java program execution and hence its nature must be static.
• Since main() method must be accessed by every java programmer and hence whose access specifier must be public.
• Each and every main() method of java must take array of objects of String.
• Block of statements represents set of executable statements which are in term calling user-defined methods are containing business-logic.
• The file naming conversion in the java programming is that which-ever class is containing main() method, that class name must be given as a file name with an extension .java.

Basic Practical.

• Write a Java program to print 'Hello' on screen and then print your name on a separate line.
• Write a Java program to print the sum of two numbers.
• Write a Java program to divide two numbers and print on the screen. 
• Write a Java program to print the result of the following operations.
• a. -5 + 8 * 6
• b. (55+9) % 9 
• c. 20 + -3*5 / 8 
• d. 5 + 15 / 3 * 2 - 8 % 3 
• Write a Java program that takes two numbers as input and display the product of two numbers. 
•  Write a Java program to print the sum (addition), multiply, subtract, divide and remainder of two numbers.
• Write a Java program that takes a number as input and prints its multiplication table upto 10.
• Write a Java program to display the following pattern.

•    J    a   v     v  a                                                  
     J   a a   v   v  a a                                                 
  J  J  aaaaa   V V  aaaaa                                                
   JJ  a     a   V  a     a

• Write a Java program to compute the specified expressions and print the output.

• ((25.5 * 3.5 - 3.5 * 3.5) / (40.5 - 4.5)) 

• Write a Java program to compute a specified formula.

• 4.0 * (1 - (1.0/3) + (1.0/5) - (1.0/7) + (1.0/9) - (1.0/11))

• Write a Java program to print the area and perimeter of a circle.
• Write a Java program that takes five numbers as input to calculate and print the average of the numbers.
• Write a Java program to print the area and perimeter of a rectangle.
• Write a Java program to print an Indian flag on the screen.
• Write a Java program to swap two variables.
• Write a Java program to print a face.

 +"""""+                                                                                                      
[| o o |]                                                                                                     
 |  ^  |                                                                                                      
 | '-' |                                                                                                      
 +-----+ 

• Write a Java program to add two binary numbers.
• Test Data:
• Input first binary number: 100010
• Input second binary number: 110010
• Write a Java program to multiply two binary numbers.
• Test Data:\

• Input first binary number: 110
• Input second binary number: 101
• Write a Java program to convert a decimal number to binary number.
• Write a Java program to convert a decimal number to hexadecimal number.
• Write a Java program to convert a decimal number to octal number.
• Write a Java program to convert a binary number to decimal number.
• Write a Java program to convert a binary number to hexadecimal number.
• Write a Java program to convert a binary number to a Octal number.
• Write a Java program to convert a hexadecimal to a decimal number.
• Write a Java program to convert a hexadecimal to a binary number.
• Write a Java program to convert a hexadecimal to a octal number.