# Reading from Keyboard in Java

**JAVA** language provides a Class called Scanner that is used for reading data from different sources.

Here **KEYBOARD is a source.**

So, ***How to read data from the keyboard?***

We have a Scanner class that is present in the UTIL package of Java.

Now, We have some methods that are necessary to read the Scanner and 
there are different methods as following:

nextInt( )
nextFloat( )
nextDouble( )
next( )
nextLine( )
nextByte( )
nextShort( )
nextLong( )
nextBoolean( )
hasNextInt( )
hasNextFloat( )

**The selection of the method depends on the type of information or data you required from a user. **

For example: 
1. If you are requesting the age of a person, then you require a number from the user. The number is an Integer type and hence, you will call the method nextInt( ) to read the numbers from the keyboard.
2. If you request a single word from the user, then use next( ).
3. If you request a collection of words or lines, then use nextLine( ).

**Let's see How to use the Scanner class with a example:**

*Step 1:*  Create Object

Scanner sc = new Scanner(System.in);

Here, Scanner(left) is a class name.
Sc is a reference.
new Scanner is a constructor.
System. in is an object associated with the Keyboard.

Example: Add any two numbers.

*Step 2:* Declare variables.

int a,b,c;

*Step 3:* Give the message to the system that you want to take some number from the keyboard.

System.out.println("Enter two numbers");

*Step 4: *For reading a number, we need to call out a method and store a value in a variable.

a = s.nextInt( );

b = s.nextInt( );

c= a+b;

Since the type of data is an Integer, we use the method nextInt( );

Once we call this [nextInt( );] method, It will read integer numbers from the keyboard.

Basically, s.nextInt( ); will get Integer from the keyboard and store in variable a and b.

*Step 5:* Print the result

System.out.println("Sum is " + c);

Example 2:
Take the name of a person as input and give the Welcome message as Output.


![Screenshot (75).png](https://cdn.hashnode.com/res/hashnode/image/upload/v1626879500054/p_gichsom.png)


**Important:**
What is a use of hasNextInt( ) and hasNextFloat?

Answer: This method is use to check if the data is an integer/float type or not before reading.

**Reminder:**
System.out.println("Hello" + c);  prints "HelloMahadev" and hence it is WRONG.
System.out.println("Hello " + c); prints "Hello Mahadev" and hence it is RIGHT.