What is the syntax for passing a Scanner object as a parameter in Java methods?

Until Java 1.5Before reading data from the user programmer, it depends on character stream classes and byte stream classes.

From Java 1.5The Scanner class is introduced. This class accepts File, InputStream, Path, and String objects, and reads all primitive data types and String tokens (from the given source) one by one using regular expressions.

By default, spaces are considered delimiters (used to split data into tokens).

Read various data types from the sourcenextXXX()The methods provided by this class,nextInt(),nextShort(),nextFloat(),nextLong(),nextBigDecimal(),nextBigInteger(),nextLong(),nextShort(),nextDouble(),nextByte(),nextFloat(),next().

Passing a Scanner object as a parameter

You can pass a Scanner object as a parameter to a method.

Example

The following Java program demonstrates how to pass a Scanner object to a method. The object reads the content of the file.

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Scanner;
public class ScannerExample {
　　　public String sampleMethod(Scanner sc){
　　　　　　StringBuffer sb = new StringBuffer();
　　　　　　while(sc.hasNext()) {
　　　　　　　　　sb.append(sc.nextLine());
　　　　　　}
　　　　　　return sb.toString();
　　　}
　　　public static void main(String args[]) throws IOException {
　　　　　　//Instantiate the inputStream class
　　　　　　InputStream stream = new FileInputStream("D:\\sample.txt");
　　　　　　//Instantiate Scanner class
　　　　　　Scanner sc = new Scanner(stream);
　　　　　　ScannerExample obj = new ScannerExample();
　　　　　　//Call Method
　　　　　　String result = obj.sampleMethod(sc);
　　　　　　System.out.println("File content:");
　　　　　　System.out.println(result);
　　　}
}

Output Result

File Content:
oldtoolbag.com originated from the idea that there exists a class of readers who respond better to on-line
content and prefer to learn new skills at their own pace from the comfort of their drawing rooms.

Example

In the following example, we create a Scanner object with standard input (System.in) as the source and pass it as a parameter to the method.

import java.io.IOException;
import java.util.Scanner;
public class ScannerExample {
　　　public void sampleMethod(Scanner sc){
　　　　　　StringBuffer sb = new StringBuffer();
　　　　　　System.out.println("Enter your name: ");
　　　　　　String name = sc.next();
　　　　　　System.out.println("Enter your age: ");
　　　　　　String age = sc.next();
　　　　　　System.out.println("Hello "+name+" You are "+age+" years old");
　　　}
　　　public static void main(String args[]) throws IOException {
　　　　　　//Instantiate Scanner class
　　　　　　Scanner sc = new Scanner(System.in);
　　　　　　ScannerExample obj = new ScannerExample();
　　　　　　//Call Method
　　　　　　obj.sampleMethod(sc);
　　　}
}

Output Result

Enter your name:
Krishna
Enter your age:
25
Hello Krishna You are　25　years old