Scanner hasNextLong(int) in Java

hasNextLong(int): This method is available in java.util.Scanner class of Java.

Syntax:

boolean java.util.Scanner.hasNextLong(int radix)

This method takes one argument. This method returns true if the next token in this scanner's input can be interpreted as a long value in the specified radix.

Parameters: One parameter is required for this method.

radix: the radix is used to interpret the token as a long value.

Returns: true if and only if this scanner's next token is a valid long value.

Throws:

1. IllegalStateException - if this scanner is closed.

2. IllegalArgumentException - if the radix is out of range

Approach 1: When no exception

Java

import java.util.Scanner;

public class ScannerhasNextLong2 {
    public static void main(String[] args) {

        String source = "Hello World";
        Scanner scanner = new Scanner(source);

        int radix = Character.MIN_RADIX;
        System.out.println(scanner.hasNextLong(radix));

        scanner.close();
    }
}

Output:

false

Approach 2: IllegalStateException

Java

import java.util.Scanner;

public class ScannerhasNextLong2 {
    public static void main(String[] args) {

        String source = "Hello World";
        Scanner scanner = new Scanner(source);

        int radix = Character.MIN_RADIX;
        scanner.close();
        System.out.println(scanner.hasNextLong(radix));

    }
}

Output:

Exception in thread "main" java.lang.IllegalStateException: Scanner closed
	at java.base/java.util.Scanner.ensureOpen(Scanner.java:1150)
	at java.base/java.util.Scanner.hasNext(Scanner.java:1540)
	at java.base/java.util.Scanner.hasNextLong(Scanner.java:2298)
	

Approach 3: IllegalArgumentException

Java

import java.util.Scanner;

public class ScannerhasNextLong2 {
    public static void main(String[] args) {

        String source = "Hello World";
        Scanner scanner = new Scanner(source);

        int radix = Character.MIN_RADIX - 1;
        System.out.println(scanner.hasNextLong(radix));

        scanner.close();
    }
}

Output:

Exception in thread "main" java.lang.IllegalArgumentException: radix:1
	at java.base/java.util.Scanner.setRadix(Scanner.java:1368)
	at java.base/java.util.Scanner.hasNextLong(Scanner.java:2297)