Java Scanner hasNextInt() Method

The hasNextInt() method of Java Scanner class is used to check if the next token in this scanner's input can be interpreted as an int value using the nextInt() method. There is two different types of Java hasNextInt() method which can be differentiated depending on its parameter. These are:

Java Scanner hasNextInt() Method
Java Scanner hasNextInt(int radix) Method

hasNextInt() Method:

This Java Scanner class method is used to check if the next token in this scanner's input can be interpreted as an int value or not in the default radix using the nextInt() method. It returns true if it can be interprated as an int value otherwise reurns false.

hasNextInt(int radix) Method:

This is an inbuilt method of Java Scanner class which is used to check if the next token in this scanner's input can be interpreted as an int value or not in the specified radix using the nextInt() method.

Syntax

Following is the declaration of hasNextInt() method:

public boolean hasNextInt()
public boolean hasNextInt(int radix)

Parameter

DataType	Parameter	Description	Required/Optional
int	radix	It is used to interpret the token as an int value.	Required

Returns

The hasNextInt() method returns true if and only if this scanner's next token is a valid int value.

Exceptions

IllegalStateException- It throws this exception if the innvocation is done after the scanner has been closed.

IllegalArgumentException- It throws this exception if the specified radix is out of range.

Compatibility Version

Java 1.5 and above

Example 1

import java.util.*;
public class ScannerHasNextIntExample1 {  
    public static void main(String args[]){  
    	//Initialize the scanner
    	Scanner scan = new Scanner(" Int number is 21");
    	//Iterate through the tokens
    	while(scan.hasNext()){
    		//Print int value
    		if(scan.hasNextInt(8)){
    			System.out.println("Found Int Value: "+scan.next());
    		}
    		else{
    			scan.next();
    		}
    	}
    	scan.close();
	}  
}

Output:

Found Int Value: 21

Example 2

import java.util.*;
public class ScannerHasNextIntExample2 {  
    public static void main(String args[]){   	
    	  String s = "Hello World! 12 + 13.0 = 15 ";
        Float f = 2.123f;
        s = s + f;
        //Create a new scanner Object
        Scanner scanner = new Scanner(s);
        //Assign locale as US to recognize int numbers in a string
        scanner.useLocale(Locale.US);
        while (scanner.hasNext()) {          
           //Check if the scanner's next token is Int
           System.out.println("Found Int Value: " + scanner.hasNextInt());
           //Print scanned input
           System.out.println("Scan Token: " + scanner.next());
           }    
        scanner.close();
	  }  
}

Output:

Found Int Value: false
Scan Token: Hello
Found Int Value: false
Scan Token: World!
Found Int Value: true
Scan Token: 12
Found Int Value: false
Scan Token: +
Found Int Value: false
Scan Token: 13.0
Found Int Value: false
Scan Token: =
Found Int Value: true
Scan Token: 15
Found Int Value: false
Scan Token: 2.123

Example 3

import java.util.*;
public class ScannerHasNextIntExample3 {  
    public static void main(String args[]){   	
    	  Scanner scan = new Scanner(System.in);
        System.out.print("Please enter value: ");    
        if(scan.hasNextInt())
        {
          int x = scan.nextInt();
          System.out.println("Your entered value: " + x);
        } 
        else {
        	System.out.println("Please entered the Integer value. ");
        }
        scan.close();
	  }  
}

Output:

Please enter value: 12345
Your entered value: 12345

Please enter value: 123.45
Please entered the Integer value.

Example 4

import java.util.*;
public class ScannerHasNextIntExample4 {  
	public static void main(String[] args) {
		//Initialize the scanner
		Scanner scan = new Scanner("55 B3 -25 -7 1D");
		while(scan.hasNext()){
			//If the next is a int, print found and the int with radix 16
	            if (scan.hasNextInt()) {
	                 System.out.println("Found :" + scan.nextInt(16));
	            }
	         //If no int is found, print "Not Found" and the token
	         System.out.println("Not Found :" + scan.next());
		}
		scan.close();
	}
}

Output:

Found :85
Not Found :B3
Found :-37
Not Found :-7
Not Found :1D

Example 5

import java.util.*;
public class ScannerHasNextIntExample5 {  
	public static void main(String[] args) {
		String str = " 11 Java 11 + 11 = 22.0";
            Scanner scanner = new Scanner(str);
            while (scanner.hasNext()) {
            	//If the next is int, print found and the int with radix
            if (scanner.hasNextInt()) {
                System.out.println("Found :" + scanner.nextInt(598670));
            }
            //If int is not found, print "Not Found" and the token
            System.out.println("Not Found :" + scanner.next());
            }
            scanner.close();
	}
}

Output:

Exception in thread "main" java.lang.IllegalArgumentException: radix:598670
	at java.base/java.util.Scanner.setRadix(Scanner.java:1368)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2254)
	at myPackage.ScannerHasNextIntExample5.main(ScannerHasNextIntExample5.java:10)

Next TopicJava Scanner Class

← prev next →

Help Others, Please Share

Javatpoint Services

JavaTpoint offers too many high quality services. Mail us on [email protected], to get more information about given services.

Website Designing
Website Development
Java Development
PHP Development
WordPress
Graphic Designing
Logo
Digital Marketing
On Page and Off Page SEO
PPC
Content Development
Corporate Training
Classroom and Online Training
Data Entry

Training For College Campus

JavaTpoint offers college campus training on Core Java, Advance Java, .Net, Android, Hadoop, PHP, Web Technology and Python. Please mail your requirement at [email protected].
Duration: 1 week to 2 week

^{Like/Subscribe us for latest updates or newsletter}