Class 9 -Scanner

Input Method:

 We are going to use Scanner for accepting values from the user . Its a simple one.

First include the package util.

import java.util.*;

Only small letters and * indicates all the files from the package and there is a semi colon in the end.

Then comes the main function

public static void main( )
{
Scanner S=new Scanner(System.in);

Remember S in red colour are capital letters. Here S is a variable can be in small or capital letter or any other variable name.

There are different statements for accepting different data type values.



int a= S.nextInt( );

float f= S.nextFloat( );

double x=S.nextDouble( );

But  accepting character and string are different.

char ch=(char)System.in.read( );

String st=S.next( );

String st1=S.nextLine( );

next( ) accepts a word till a space and keeps the cursor in the same line.
 
nextLine( ) accepts words and moves the cursor to the next line after accepting the value.

Let us accept two numbers.

import java.util.*; ------------------------------------ 1

class ex1
{
public static void main( )
{
  Scanner s=new Scanner(System.in); --------------- 2
int a, b,sum; --------------------------------------------- 3
System.out.println("Enter the first number"); ------ 4
a=s.nextInt( ); ------------------------------------------- 5
System.out.println("Enter the second number");----- 4
b=s.nextInt( );-------------------------------------------- 5
sum=a+b; -------------------------------------------------6
System.out.print("Total = " +sum);------------------- 7
}
}
 
 1  is the first line in the program.
 
 2  Write any variable instead of s , if you want.

 3  is variable declaration.

 4 is just a prompt message. A remainder to the user to enter a number.

5 Since I am accepting integer values, it should be nextInt. Remember no space  after next and I in Int is capital.

6 is the calculation

7 is the output.


 For other programs step 3 and step 5 will be different according to the data type you use.