call by value and call y refrence in java
/*call by refrence doesnot change the value of parameters(a and b ) in
main function but where as passing the values by refrence changes the values
of and b in the main function
*/
//CALL BY REFERENCE
public class JavaTester {
public static void main(String[] args) {
IntWrapper a = new IntWrapper(30);
IntWrapper b = new IntWrapper(45);
System.out.println("Before swapping, a = " + a.a + " and b = " + b.a);
// Invoke the swap method
swapFunction(a, b);
System.out.println("\n**Now, Before and After swapping values will be different here**:");
System.out.println("After swapping, a = " + a.a + " and b is " + b.a);
}
public static void swapFunction(IntWrapper a, IntWrapper b) {
System.out.println("Before swapping(Inside), a = " + a.a + " b = " + b.a);
// Swap n1 with n2
IntWrapper c = new IntWrapper(a.a);
a.a = b.a;
b.a = c.a;
System.out.println("After swapping(Inside), a = " + a.a + " b = " + b.a);
}
}
class IntWrapper {
public int a;
public IntWrapper(int a){ this.a = a;}
}
/*
------------------------------------OUTPUT--------------------------------------
Before swapping, a = 30 and b = 45
Before swapping(Inside), a = 30 b = 45
After swapping(Inside), a = 45 b = 30
**Now, Before and After swapping values will be different here**:
After swapping, a = 45 and b is 30
--------------------------------------------------------------------------------
*/
//CALL BY VALUE
public class Tester{
public static void main(String[] args){
int a = 30;
int b = 45;
System.out.println("Before swapping, a = " + a + " and b = " + b);
// Invoke the swap method
swapFunction(a, b);
System.out.println("\n**Now, Before and After swapping values will be same here**:");
System.out.println("After swapping, a = " + a + " and b is " + b);
}
public static void swapFunction(int a, int b) {
System.out.println("Before swapping(Inside), a = " + a + " b = " + b);
// Swap n1 with n2
int c = a;
a = b;
b = c;
System.out.println("After swapping(Inside), a = " + a + " b = " + b);
}
}
/*
-----------------------------------OUTPUT---------------------------------------
Before swapping, a = 30 and b = 45
Before swapping(Inside), a = 30 b = 45
After swapping(Inside), a = 45 b = 30
**Now, Before and After swapping values will be same here**:
After swapping, a = 30 and b is 45
--------------------------------------------------------------------------------
*/