Type Conversion and Casting

Command-line arguments:
-These are the values we pass to main() from the command line.
Note: Observe the parameter type of main()--->Its a String type array.

Example:
Q) class Check{
public static void main(String[] ar){
System.out.println(ar[0]);
System.out.println(ar[1]);
 }
}
File name: Check.java
Compilation:
>javac Check.java
Execution:
>java Check hello hi
hello
hi
.........................................................
Q) class Check1{
public static void main(String[] ar){
System.out.println(ar[0]+ar[1]);
 }
}
File name: Check1.java
Compilation:
> javac Check1.java
Execution:
> java Check1 10 20
1020
........................................................
Q) class Check2{
public static void main(String[] ar){
int x=Integer.parseInt(ar[0]);//parseInt() converts 'String' value to its corresponding 'int' type value
int y=Integer.parseInt(ar[1]);
System.out.println(x+y);
 }
}
File name: Check2.java
Compilation:
>javac Check2.java
Execution:
>java Check2 10 20
30
.......................................................