Scanner nextLong() method in Java with Examples
Last Updated :
12 Oct, 2018
The
nextLong(radix) method of
java.util.Scanner class scans the next token of the input as a long. If the translation is successful, the scanner advances past the input that matched. If the parameter radix is not passed, then it behaves similarly as nextLong(radix) where the radix is assumed to be the default radix.
Syntax:
public long nextLong()
Parameters: The function accepts a parameter
radix which is used to interpret the token as a long value.
Return Value: This function returns the long scanned from the input.
Exceptions: The function throws three exceptions as described below:
- InputMismatchException: if the next token does not matches the Integer regular expression, or is out of range
- NoSuchElementException: throws if input is exhausted
- IllegalStateException: throws if this scanner is closed
Below programs illustrate the above function:
Program 1:
Java
// Java program to illustrate the
// nextLong() method of Scanner class in Java
// without parameter
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
String s = "Gfg 9 + 6 = 12.0";
// create a new scanner
// with the specified String Object
Scanner scanner = new Scanner(s);
while (scanner.hasNext()) {
// if the next is a Long,
// print found and the Long
if (scanner.hasNextLong()) {
System.out.println("Found Long value :"
+ scanner.nextLong());
}
// if no Long is found,
// print "Not Found:" and the token
else {
System.out.println("Not found Long value :"
+ scanner.next());
}
}
scanner.close();
}
}
Output:
Not found Long value :Gfg
Found Long value :9
Not found Long value :+
Found Long value :6
Not found Long value :=
Not found Long value :12.0
Program 2:
Java
// Java program to illustrate the
// nextLong() method of Scanner class in Java
// with parameter
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
String s = "Gfg 9 + 6 = 12.0";
// create a new scanner
// with the specified String Object
Scanner scanner = new Scanner(s);
while (scanner.hasNext()) {
// if the next is a Long,
// print found and the Long
if (scanner.hasNextLong()) {
System.out.println("Found Long value :"
+ scanner.nextLong(12));
}
// if no Long is found,
// print "Not Found:" and the token
else {
System.out.println("Not found Long value :"
+ scanner.next());
}
}
scanner.close();
}
}
Output:
Not found Long value :Gfg
Found Long value :9
Not found Long value :+
Found Long value :6
Not found Long value :=
Not found Long value :12.0
Program 3: To demonstrate InputMismatchException
Java
// Java program to illustrate the
// nextLong() method of Scanner class in Java
// InputMismatchException
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
try {
String s = "Gfg 9 + 6 = 12.0";
// create a new scanner
// with the specified String Object
Scanner scanner = new Scanner(s);
while (scanner.hasNext()) {
// if the next is a Long,
// print found and the Long
// since the value 60 is out of range
// it throws an exception
System.out.println("Next Long value :"
+ scanner.nextLong());
}
scanner.close();
}
catch (Exception e) {
System.out.println("Exception thrown: " + e);
}
}
}
Output:
Exception thrown: java.util.InputMismatchException
Program 4: To demonstrate NoSuchElementException
Java
// Java program to illustrate the
// nextLong() method of Scanner class in Java
// NoSuchElementException
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
try {
String s = "Gfg";
// create a new scanner
// with the specified String Object
Scanner scanner = new Scanner(s);
// Trying to get the next Long value
// more times than the scanner
// Hence it will throw exception
for (int i = 0; i < 5; i++) {
// if the next is a Long,
// print found and the Long
if (scanner.hasNextLong()) {
System.out.println("Found Long value :"
+ scanner.nextLong());
}
// if no Long is found,
// print "Not Found:" and the token
else {
System.out.println("Not found Long value :"
+ scanner.next());
}
}
scanner.close();
}
catch (Exception e) {
System.out.println("Exception thrown: " + e);
}
}
}
Output:
Not found Long value :Gfg
Exception thrown: java.util.NoSuchElementException
Program 5: To demonstrate IllegalStateException
Java
// Java program to illustrate the
// nextLong() method of Scanner class in Java
// IllegalStateException
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
try {
String s = "Gfg 9 + 6 = 12.0";
// create a new scanner
// with the specified String Object
Scanner scanner = new Scanner(s);
// close the scanner
scanner.close();
System.out.println("Scanner Closed");
System.out.println("Trying to get "
+ "next Long value");
while (scanner.hasNext()) {
// if the next is a Long,
// print found and the Long
if (scanner.hasNextLong()) {
System.out.println("Found Long value :"
+ scanner.nextLong());
}
// if no Long is found,
// print "Not Found:" and the token
else {
System.out.println("Not found Long value :"
+ scanner.next());
}
}
}
catch (Exception e) {
System.out.println("Exception thrown: " + e);
}
}
}
Output:
Scanner Closed
Trying to get next Long value
Exception thrown: java.lang.IllegalStateException: Scanner closed
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#nextLong(int)
Similar Reads
Java Tutorial Java is a high-level, object-oriented programming language used to build web apps, mobile applications, and enterprise software systems. It is known for its Write Once, Run Anywhere capability, which means code written in Java can run on any device that supports the Java Virtual Machine (JVM).Java s
10 min read
Java OOP(Object Oriented Programming) Concepts Java Object-Oriented Programming (OOPs) is a fundamental concept in Java that every developer must understand. It allows developers to structure code using classes and objects, making it more modular, reusable, and scalable.The core idea of OOPs is to bind data and the functions that operate on it,
13 min read
Java Interview Questions and Answers Java is one of the most popular programming languages in the world, known for its versatility, portability, and wide range of applications. Java is the most used language in top companies such as Uber, Airbnb, Google, Netflix, Instagram, Spotify, Amazon, and many more because of its features and per
15+ min read
Arrays in Java Arrays in Java are one of the most fundamental data structures that allow us to store multiple values of the same type in a single variable. They are useful for storing and managing collections of data. Arrays in Java are objects, which makes them work differently from arrays in C/C++ in terms of me
15+ min read
Collections in Java Any group of individual objects that are represented as a single unit is known as a Java Collection of Objects. In Java, a separate framework named the "Collection Framework" has been defined in JDK 1.2 which holds all the Java Collection Classes and Interface in it. In Java, the Collection interfac
15+ min read
Inheritance in Java Java Inheritance is a fundamental concept in OOP(Object-Oriented Programming). It is the mechanism in Java by which one class is allowed to inherit the features(fields and methods) of another class. In Java, Inheritance means creating new classes based on existing ones. A class that inherits from an
13 min read
Java Exception Handling Exception handling in Java allows developers to manage runtime errors effectively by using mechanisms like try-catch block, finally block, throwing Exceptions, Custom Exception handling, etc. An Exception is an unwanted or unexpected event that occurs during the execution of a program, i.e., at runt
10 min read
Java Programs - Java Programming Examples In this article, we will learn and prepare for Interviews using Java Programming Examples. From basic Java programs like the Fibonacci series, Prime numbers, Factorial numbers, and Palindrome numbers to advanced Java programs.Java is one of the most popular programming languages today because of its
8 min read
Java Interface An Interface in Java programming language is defined as an abstract type used to specify the behaviour of a class. An interface in Java is a blueprint of a behaviour. A Java interface contains static constants and abstract methods. Key Properties of Interface:The interface in Java is a mechanism to
12 min read
Introduction to Java Java is a high-level, object-oriented programming language developed by Sun Microsystems in 1995. It is platform-independent, which means we can write code once and run it anywhere using the Java Virtual Machine (JVM). Java is mostly used for building desktop applications, web applications, Android
4 min read