Scanner nextInt(int) in Java

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

Syntax:

int java.util.Scanner.nextInt(int radix)

This method takes one argument. This method scans the next token of the input as an int.

Parameters: One parameter is required for this method.

radix: the radix is used to interpret the token as an int value.

Returns: the int scanned from the input.

Throws:

1. InputMismatchException - if the next token does not match the Integer regular expression, or is out of range.

2. NoSuchElementException - if input is exhausted.

3. IllegalStateException - if this scanner is closed.

4. IllegalArgumentException - if the radix is out of range

Approach 1: When no exception

Java

import java.util.Scanner;

public class ScannernextInt2 {
    public static void main(String[] args) {

        String source = "100101 Hello World";
        Scanner scanner = new Scanner(source);

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

        scanner.close();
    }
}

Output:

37

Approach 2: InputMismatchException

Java

import java.util.Scanner;

public class ScannernextInt2 {
    public static void main(String[] args) {

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

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

        scanner.close();
    }
}

Output:

Exception in thread "main" java.util.InputMismatchException
	at java.base/java.util.Scanner.throwFor(Scanner.java:939)
	at java.base/java.util.Scanner.next(Scanner.java:1594)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2258)
	

Approach 3: NoSuchElementException 

Java

import java.util.Scanner;

public class ScannernextInt2 {
    public static void main(String[] args) {

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

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

        scanner.close();
    }
}

Output:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Scanner.throwFor(Scanner.java:937)
	at java.base/java.util.Scanner.next(Scanner.java:1594)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2258)
	

Approach 4: IllegalStateException 

Java

import java.util.Scanner;

public class ScannernextInt2 {
    public static void main(String[] args) {

        String source = "100101 Hello World";
        Scanner scanner = new Scanner(source);

        int radix = Character.MIN_RADIX;

        scanner.close();
        System.out.println(scanner.nextInt(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.next(Scanner.java:1573)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2258)
	

Approach 5: IllegalArgumentException 

Java

import java.util.Scanner;

public class ScannernextInt2 {
    public static void main(String[] args) {

        String source = "100101 Hello World";
        Scanner scanner = new Scanner(source);

        int radix = Character.MIN_RADIX - 1;
        System.out.println(scanner.nextInt(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.nextInt(Scanner.java:2254)