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/* 01 - sT Var. In Cls. : WORKS FINE */
class K02 {
int a =10;
static int b = 20;
void m1(){
int c =30;
}
public static void main(String[] args) {
}
}
/*02 - sT Var. In M/t. : ILLEGAL START OF EXPRESSION */
class K02 {
int a =10;
static int b = 20;
void m1(){
static int c =30;
}
public static void main(String[] args) {
}
}
/*03 - sT Var. Can't Directly Access In Another cls.. : CANNOT FIND SYMBOL */
public class K02 {
static int a = 20;
}
class book {
public static void main(String[] args) {
System.out.println(a);
}
}
/*04 - sT Var. Can Directly Access In Another cls. Using cls. Name. : 20*/
public class K02 {
static int a = 20;
}
class book {
public static void main(String[] args) {
System.out.println(K02.a);
}
}
// s/T v/R belongs to the class not the object
/*05 - Non sT Var. Can Not Access In Another sT cls. Using cls. Name.
: NON-STATIC VAIRABLE A CANNOT BE REFERED FORM A STATIC CONTEXT */
public class K02 {
int a = 20;
}
class book {
public static void main(String[] args) {
System.out.println(K02.a);
}
}
/*06 - employee obj. init. ( id,name,comp) using c/t , w/o using sT */
public class K02 {
public static void main(String[] args) {
Employee e1 = new Employee(101, "Rajat", "kb");
e1.display();
Employee e2 = new Employee(102, "Deepak", "kb");
e2.display();
Employee e3 = new Employee(103, "Manoj", "kb");
e3.display();
}
}
class Employee {
int empid;
String emp_name;
String emp_comp;
Employee(int empid, String emp_name, String emp_comp){
this.empid=empid;
this.emp_name=emp_name;
this.emp_comp=emp_comp;
}
void display(){
System.out.println(empid+" "+emp_comp+" "+ emp_name);
}
}
// 101 kb Rajat
// 102 kb Deepak
// 103 kb Manoj
/*07 - employee obj. init. ( id,name,comp) using c/t , with sT comp. */
public class K02 {
public static void main(String[] args) {
Employee e1 = new Employee(101, "Rajat");
e1.display();
Employee e2 = new Employee(102, "Deepak");
e2.display();
Employee e3 = new Employee(103, "Manoj");
e3.display();
}
}
class Employee {
int empid;
String emp_name;
static String emp_comp ="kb";
Employee(int empid, String emp_name){
this.empid=empid;
this.emp_name=emp_name;
}
void display(){
System.out.println(empid+" "+emp_comp+" "+ emp_name);
}
}
// 101 kb Rajat
// 102 kb Deepak
// 103 kb Manoj
/*08 - counter program using instance Var..*/
public class K02 {
int count=0;
K02(){
count++;
System.out.println(count);
}
public static void main(String[] args) {
K02 k1 = new K02(); // 1
K02 k2 = new K02(); // 1
K02 k3 = new K02(); // 1
K02 k4 = new K02(); // 1
}
}
// The static variable gets memory only once in the
// class area at the time of class loading.
/*09 - counter program using sT Var.. */
public class K02 {
static int count=0;
K02(){
count++;
System.out.println(count);
}
public static void main(String[] args) {
K02 k1 = new K02(); // 1
K02 k2 = new K02(); // 2
K02 k3 = new K02(); // 3
K02 k4 = new K02(); // 4
}
}
/*10 - non sT m/t call within cls using obj. */
public class K02 {
void display(){
System.out.println("display method");
}
public static void main(String[] args) {
K02 k1 = new K02();
k1.display();
}
}
/*11 - non sT m/t call within cls. w/o using obj. */
public class K02 {
void display(){
System.out.println("display method");
}
public static void main(String[] args) {
display();
}
}
// non-static method display() cannot be referenced from a static context display();
/*12 - sT m/t call within cls. using cls. name and directly */
public class K02 {
static void display(){
System.out.println("display method");
}
public static void main(String[] args) {
display(); // works
K02.display(); // works
}
}
// display method
// display method
/*13 - cant not cal sT m/t by other cls. directly. */
public class K02 {
static void display(){
System.out.println("display method");
}
public static void main(String[] args) {
pen();
}
}
class Book {
static void pen(){
System.out.println("this is my pen");
}
}
// cannot find symbol pen();
/*14 - sT m/t call by other cls. using cls name, */
public class K02 {
static void display(){
System.out.println("display method");
}
public static void main(String[] args) {
Book.pen();
}
}
class Book {
static void pen(){
System.out.println("this is my pen");
}
}
// this is my pen
/*15 - sT m/t can only access sT data. */
public class K02 {
int i =10;
static void display(){
System.out.println(i);
}
}
// non-static variable i cannot be referenced from a static context
// System.out.println(i);
/*16 - sT m/t can call only sT m/t directly. */
public class K02 {
int i =10;
static void display(){
show();
System.out.println("hi");
}
void show(){
System.out.println("hello");
}
}
// non-static method show() cannot be referenced from a static context
/*17 - sT m/t Cannot Refer To 'This' Or 'Super' Keyword In Anyway. */
public class K02 {
int i =10;
static void display(){
System.out.println(this.i);// can not use super also
}
}
// non-static variable this cannot be referenced from a static context
/*18 - Only sT Block Executes Automatically When The Cls. Is Loaded In The Memory. */
public class K02 {
static{
System.out.println("hello");
}
}
// Main method not found in class K19, please define the main method as:
// public static void main(String[] args)
/*19 - Only sT Block With Main M/T sT Block Executes First Then Main m/t. */
public class K02 {
static{ //1
System.out.println("hello");
}
public static void main(String[] args) { //2
System.out.println("hi....");
}
}
// hello
// hi....
/*20 - Multiple sT Block In cls., Executes Top To Bottom, sT Members Executes First. */
public class K02 {
static{ // 1
System.out.println("static block first");
}
public static void main(String[] args) { // 3
System.out.println("main block at last");
}
static{ // 2
System.out.println("static block second");
}
}
// static block first
// static block second
// main block at last
