2. Tips and Tricks
Follow the naming Convention Rule
Meaning full name
Different variable different name in same scope
Variables based on scopes
No keyword no reserve word(remember the color)
Don’t start with digit
Single name is variable
Verb or action is method followed by ()
Small case with underscore and camel case are methods and variables
Word with Capital letter at start is Class name
All small letter in word is package
3. Tips and Tricks
String firstName → variable to hold first name
void saveName() → method
Person → Class
4. Variable
Class or instance variable
Inside class with the scope within class
Static variable
Whose value doesn’t change
Local variable
Inside method with the scope within method
5. Methods
Static Method Non Static Method
Method with
Return type and
Argument
Method with no
Return type and
No Argument
Method with no
Return type and
Argument
Method with
Return type and
No Argument
6. Code Example
public class TestOne {
int n2 = 20; //class variable or instance variable
static int n3 = 30; //static variable
static char c1 ;
String str2;
public static void main(String[] args) {
int n1 = 10; //local variable
System.out.println("the value of a is : "+n1);
//System.out.println(n2);cant be called here because non static field cant be called inside static method
System.out.println(n3);
showValue(); //since this is static method
TestOne tOne = new TestOne();
tOne.display();
c1 = 'J';
System.out.println(c1);
}
public static void showValue(){//static method with no return type and no argument
System.out.println(n3);
//System.out.println(n1);cant be called here because local variable at main method
}
public void display(){//non static method with no return type and no argument
System.out.println(n2);
System.out.println(n3);
String str1 = "hello world";
System.out.println(str1);
str2 = "Hello test";
}
}