Programming elements in Java

Programming elements:

• Software is a set of programs.
• Every program consists 3 things
  • Identity
  • Variables
  • Methods

Identity:

• Every program has unique identity.
• We can access programs with identities only.
• For example Account Holder program can access uniquely using account number as identity.

Variable:

• Variables are used to store information.
• Programs share information in communication.

Function:

• Also called functions(In procedure oriented programming)
• Functions are used in communication.

Application: Banking project

• We design Account holder programs
• Account holder consists
  • Identity: account number
  • Variables: name, balance, pin, mobile, mail, address…
  • Methods: withdraw(), deposit(), transfer()….

Variables:

• Setting identities to memory locations by which we can store and process the data(modify, delete, print) easily.
• Named memory location(simple definition)

Methods:

• A block of instructions performs a task.
• We can access the block  using its identity
• Method takes input, process input and return output.

Syntax:
	returntype identity(arguments)
	{
		-> Process arguments (input)
		-> Return output
	}

Example:
	int add(int a, int b)
	{
		int c = a+b;
		return c;
	}

Banking App:
	message withdraw(atm, pin, amount)
	{
		-> ATM card is authorized or not
		-> PIN is valid or not
		-> Amount is present or not
		-> Process account
		-> Update account
		-> Release cash
	}

Every Method consists:

• Method definition:
  • It is a block
  • It contains method logic to perform task
  • It will not execute automatically.
• Method call:
  • It is a single statement.
  • It is used to access method logic.