Java.util.Scanner.nextDouble() Method

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Description

The java.util.Scanner.nextDouble() method scans the next token of the input as a double. This method will throw InputMismatchException if the next token cannot be translated into a valid double value. If the translation is successful, the scanner advances past the input that matched.

Declaration

Following is the declaration for java.util.Scanner.nextDouble() method

public double nextDouble()

Parameters

  • NA

Return Value

This method returns the double scanned from the input

Exception

  • InputMismatchException -- if the next token does not match the Float regular expression, or is out of range

  • NoSuchElementException -- if the input is exhausted

  • IllegalStateException -- if this scanner is closed

Example

The following example shows the usage of java.util.Scanner.nextDouble() method.

package com.tutorialspoint;

import java.util.*;

public class ScannerDemo {

   public static void main(String[] args) {

      String s = "Hello World! 3 + 3.0 = 6 true";

      // create a new scanner with the specified String Object
      Scanner scanner = new Scanner(s);

      // use US locale to be able to identify doubles in the string
      scanner.useLocale(Locale.US);

      // find the next double token and print it
      // loop for the whole scanner
      while (scanner.hasNext()) {

         // if the next is a double, print found and the double
         if (scanner.hasNextDouble()) {
            System.out.println("Found :" + scanner.nextDouble());
         }

         // if a double is not found, print "Not Found" and the token
         System.out.println("Not Found :" + scanner.next());
      }

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

Let us compile and run the above program, this will produce the following result:

Not Found :Hello
Not Found :World!
Found :3.0
Not Found :+
Found :3.0
Not Found :=
Found :6.0
Not Found :true



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