How to take input from user in java using scanner

• We are having special classes to take input from the user. One of the most commonly used class is java.util.Scanner.
• We can read input from the console using scanner class.
• Java.util.Scanner class provides lot of methods to take different typed of data from the user as input.
• Scanner class is final class in java like String class. 
• Scanner class implements Iterator and Closeable  interfaces.

Scanner class in Java

1. public final class Scanner
2. extends Object
3. implements Iterator<String>, Closeable

• In order to read or take input from user we need to create object of Scanner class by using its constructor which takes System.in as an argument.
• By using methods of System class we can take different type of data like string , int and float etc.
• scannerObject.nextInt() will accepts integer value as an input .
• scannerObject.nextLong() will accepts long value as an input from user.
• We also take different type of data by using  some delimiters 
• Using useDelimiter() method we can give data by using delimiters.
• Lets see what are the different methods in java.util.scanner class.

Java.util.Scanner class methods:

Scanner class in java programming:

• Lets see some simple java programs to get input from user 
• How to take integer input from user in java?
• How to take input from user in java using scanner ?
• How to take string input in java using scanner class?
  

Program #1: Write a java example program to read integer type of data as an input from the user from console using scanner class

1. package com.scannerjava;
2. 
   
3. import java.util.Scanner;
4. 
   
5. public class TakeInputUsingScanner {
6. 
   
7. /**
8.    * @wesite:www.instanceofJava.com
9.    * @category: Java program to take input from user using scanner
10.    */
11. public static void main(String[] args) {
14.     Scanner sc= new Scanner(System.in);
16.      System.out.println("Please enter any integer value as input");
17.       int x=sc.nextInt();
19.       System.out.println("Entered integer value is "+x);
20. 
    
21. }
22. }

 Output:

1. Please enter any integer value as input
2. 33
3. Entered integer value is 33

Program #2: Write a java example program to read String type of data as an input from the user from console using scanner class

1. package com.scannerjava;
2. 
   
3. import java.util.Scanner;
4. 
   
5. public class TakeInputUsingScanner {
6. 
   
7. /**
8.    * @wesite:www.instanceofJava.com
9.    * @category: Java program to take input from user using scanner
10.    */
11. public static void main(String[] args) {
14.     Scanner sc= new Scanner(System.in);
16.      System.out.println("Please enter any Sting value as input");
17.      String str=sc.next();
19.       System.out.println("Entered String value is "+str);
20. 
    
21. }
22. }
23. 
    

 Output:

1. Please enter any String value as input
2. instanceofjava
3. Entered String value is instanceofjava

Program #3: Write a java example program to read  data as an input from the user from console using scanner class with delimiters

1. package com.scannerjava;
2. 
   
3. import java.util.Scanner;
4. 
   
5. public class TakeInputUsingScanner {
6. 
   
7. /**
8.    * @wesite:www.instanceofJava.com
9.    * @category: Java program to take input from user using scanner
10.    */
11. public static void main(String[] args) {
12.  
13. String input = "top 10 java interview questions on scanner class";
14.  Scanner sc = new Scanner(input).useDelimiter("\\s");  
15.  
16.      System.out.println(sc.next());  
17.      System.out.println(sc.nextInt());  
18.      System.out.println(sc.next());  
19.      System.out.println(sc.next());  
20.      System.out.println(sc.next());  
21.      System.out.println(sc.next());  
22.      System.out.println(sc.next());    
23.       System.out.println(sc.next()); 
24. }
25. }
26. 
    

 Output:

1. top
2. 10
3. java
4. interview
5. questions
6. on
7. scanner
8. class

Program #4: Write a java example program to read  all type of data as an input from the user from console using scanner class

1. package com.scannerjava;
2. 
   
3. import java.util.Scanner;
4. 
   
5. public class TakeInputUsingScanner {
6. 
   
7. /**
8.    * @wesite:www.instanceofJava.com
9.    * @category: Java program to take input from user using scanner
10.    */
11. public static void main(String[] args) {
12.  
13. Scanner sc = new Scanner(System.in);
14.  
15.  System.out.println("Enter an integer value");
16. System.out.println(sc.nextInt()); 
17.  
18. System.out.println("Enter a float value");
19.  System.out.println(sc.nextFloat()); 
20.  
21.  System.out.println("Enter a Double value");
22. System.out.println(sc.nextDouble()); 
23.  
24. System.out.println("Enter a Byte value");
25. System.out.println(sc.nextByte()); 
26.  
27. System.out.println("Enter a Long value");
28. System.out.println(sc.nextLong());
29. }
30. }
31. 
    

 Output:

1. Enter an integer value
2. 12
3. 12
4. Enter a float value
5. 12.34
6. 12.34
7. Enter a Double value
8. 12.3456789
9. 12.3456789
10. Enter a Byte value
11. 2
12. 2
13. Enter a Long value
14. 9876636363536
15. 9876636363536

Program #5: Write a java example program how to read input from console in java eclipse  all type of data as an input from the user from console using scanner class.