Java Utility Library

Java Scanner - hasNextLong() Method



The java.util.Scanner.hasNextLong() method returns true if the next token in the scanner's input can be interpreted as a long value in the default radix using the nextLong() method. The scanner does not advance past any input.

Syntax

public boolean hasNextLong()

Parameters

No parameter is required.

Return Value

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

Exception

Throws IllegalStateException, if the scanner is closed.

Example:

In the example below, the java.util.Scanner.hasNextLong() method is used to check whether the scanner's next token is a valid long value or not.

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()) {
      //check if the next token is a long
      //if yes, prints long value
      if(MyScan.hasNextLong())
        System.out.println("Long value is: "+ MyScan.nextLong());
      //if the next token is not a long
      else
        System.out.println("No Long Value found: "+ MyScan.next());
    }

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

The output of the above code will be:

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

❮ Java.util - Scanner