Java Scanner - nextInt() Method

The java.util.Scanner.nextInt() method is used to scan the next token of the input as an int. An invocation of this method of the form nextInt() behaves in exactly the same way as the invocation nextInt(radix), where radix is the default radix of this scanner.

Syntax

public int nextInt()

Parameters

No parameter is required.

Return Value

Returns the int scanned from the input.

Exception

• Throws InputMismatchException, if the next token does not match the Float regular expression, or is out of range.
• Throws NoSuchElementException, if input is exhausted.
• Throws IllegalStateException, if this scanner is closed.

Example:

In the example below, the java.util.Scanner.nextInt() method is used to scan the next token of the input as an int.

import java.util.*;

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

    //String to scan
    String MyString = "Hello World 10 + 20 = 30.0";

    //creating a Scanner
    Scanner MyScan = new Scanner(MyString);

    while(MyScan.hasNext()) {
      //if the next is an int
      if(MyScan.hasNextInt())
        System.out.println("Int value is: "+ MyScan.nextInt());
      //if the next is not an int
      else
        System.out.println("No Int Value found: "+ MyScan.next());
    }

    //close the scanner
    MyScan.close();
  }
}

The output of the above code will be:

No Int Value found: Hello
No Int Value found: World
Int value is: 10
No Int Value found: +
Int value is: 20
No Int Value found: =
No Int Value found: 30.0