Java.util.Scanner.hasNextDouble() Method


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Description

The java.util.Scanner.hasNextDouble() method returns true if the next token in this scanner's input can be interpreted as a double value using the nextDouble() method. The scanner does not advance past any input.

Declaration

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

public boolean hasNextDouble()

Parameters

  • NA

Return Value

This method returns true if and only if this scanner's next token is a valid double value

Exception

  • IllegalStateException -- if this scanner is closed

Example

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

package com.tutorialspoint;

import java.util.*;

public class ScannerDemo {

   public static void main(String[] args) {

   String s = "Hello World! 3 + 3.0 = 6 ";
   Double d=1.3985;
   s=s+d;

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

   // assign locale as US to recognize double numbers in a string
   scanner.useLocale(Locale.US);
      
   while (scanner.hasNext()) {
   // check if the scanner's next token is a double
   System.out.println("" + scanner.hasNextDouble());

   // print what is scanned
   System.out.println("" + scanner.next());
   }

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

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

false
Hello
false
World!
true
3
false
+
true
3.0
false
=
true
6
true
1.3985

java_util_scanner.htm

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