20. Read Input From Command Line In Java


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How To Read Input From Command Line In Java Using Scanner

Scanner class is used to read input from command line. Scanner class is in java.util package. Scanner class has methods like nextInt(), nextFloat(), nextDouble() etc which read numeric data without any need of parsing using Integer.parseInt()  etc. These methods will throw an exception if you pass string or char type value.

Example:

/**
 * This program is used to read input using Scanner Class.
 * @author java tutorial
 */
public class ReadInputUsingScanner {
       public static void main(String args[]){
       //create a scanner class object.
       Scanner scanner = new Scanner(new 
           InputStreamReader(System.in));
       System.out.println("Enter your full name: ");  
 
      //read a line using scanner object.
      String userName = scanner.nextLine();
      System.out.println("Enter your full age: ");  
 
      //read an integer using scanner object.
      int age = scanner.nextInt(); 
 
       //print input values
       System.out.println("User name : " + userName);
       System.out.println("User age : " + age);
    }
}

Output:

Enter your full name:
jai
Enter your full age:
27
User name : jai
User age : 27

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