linked list in java

 class link {

class node {

int data;

node next;

node(int data) {

this.data = data;

this.next = null;

}

}

node head;

int size = 0;

void add(int data) {

node cu = new node(data);

if (size == 0) {

System.out.println("adding data is " + data);

++size;

head = cu;

} else {

System.out.println("adding data is " + data);

++size;

cu.next = head;

head = cu;

}

}

void del() {

if (size == 0) {

System.out.println("there is no node exits ");

} else {

System.out.println("deleting data is " + head.data);

head = head.next;

--size;

}

}

void print() {

if (size == 0) {

System.out.println("there is nothing to print");

} else {

System.out.println("your data is ");

node temp = head;

while (temp != null) {

System.out.println(" " + temp.data);

temp = temp.next;

}

}

}

void change(int data) {

if (size == 0) {

System.out.println("changing data null " + " to " + data);

node temp = new node(data);

head = temp;

++size;

} else {

System.out.println("changing data " + head.data + " to " + data);

head.data = data;

}

}

public static void main(String ar[]) {

link ok = new link();

ok.change(89);

ok.add(999);

ok.add(3000);

ok.print();

}

}