Java Scanner examples
Long live the Scanner
class, a few examples for self-reference.
1. Read Input
1.1 Read input from the console.
JavaScanner1.java
package com.mkyong.io;
import java.util.Scanner;
public class JavaScanner1 {
public static void main(String[] args) {
try (Scanner scanner = new Scanner(System.in)) {
System.out.print("Please enter your name: ");
String input = scanner.nextLine();
System.out.println("name : " + input);
System.out.print("Please enter your age: ");
int age = scanner.nextInt();
System.out.println("age : " + age);
}
}
}
2. Split Input
2.1 By default, the Scanner
uses whitespace as delimiters to break its input into tokens.
JavaScanner2.java
package com.mkyong.markdown;
import java.util.Scanner;
public class JavaScanner2 {
public static void main(String[] args) {
String input = "1,2,3,4,5";
try (Scanner s = new Scanner(input).useDelimiter(",")) {
while (s.hasNext()) {
System.out.println(s.next());
}
}
}
}
Output
1
2
3
4
5
3. Read File
3.1 We also can use Scanner
to read a file.
JavaScanner3.java
package com.mkyong.io;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class JavaScanner3 {
public static void main(String[] args) {
try (Scanner sc = new Scanner(new File("/home/mkyong/projects/pom.xml"))) {
while (sc.hasNext()) {
System.out.println(sc.nextLine());
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
Java library to scanner java class? Use burningwave.org !!
Thanks, you can try
var
, eg:try (var sc = new Scanner(System.in)){}