How To Get User Input in Java

Sentry Answers>Java>

Venter C.

—December 15, 2024

The Problem

I don’t know how to get user input from the console in Java.

The Solution

The most common way to get user input in Java is to use the Scanner class from the java.util package.

For example, the following code uses Scanner with methods such as nextLine() to retrieve different data inputs:

Click to Copy

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter your name: ");
        String name = scanner.nextLine(); // Read a full line of text
        System.out.println("Hello, " + name + "!");

        System.out.print("Enter your age: ");
        int age = scanner.nextInt(); // Read an integer input
        System.out.println("You are " + age + " years old.");

        System.out.print("Enter a decimal number: ");
        double number = scanner.nextDouble(); // Read a double input
        System.out.println("You entered: " + number);

        scanner.close(); // Close the scanner to free resources
    }
}

This demonstrates the following commonly used methods for reading user input:

The nextLine() method reads a full line of text.
The nextInt() method reads an integer.
The nextDouble() method reads a double.

While each method gets a different data type, the Java Scanner class does not offer a native means of reading character input.

If you need to read a single character, you can use nextLine() to fetch a line of text, then extract the first character of that line:

Click to Copy

System.out.print("Enter a character: ");
char ch = scanner.nextLine().charAt(0); // Read first character from input
System.out.println("You entered: " + ch);

You can use try-catch blocks to prevent the program from crashing when invalid input is entered:

Click to Copy

import java.util.InputMismatchException;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        try {
            System.out.print("Enter an integer: ");
            int number = scanner.nextInt();
            System.out.println("You entered: " + number);
        } catch (InputMismatchException e) {
            System.out.println("Invalid input! Please enter a valid integer.");
        }

        scanner.close();
    }
}

Products

Integrations

SDKs

Learn

Support

Hang out with us

Unsnag Your Mobile Monitoring: Why Teams Are Switching to Sentry

How To Get User Input in Java

The Problem

The Solution

Further Reading

Unsnag Your Mobile Monitoring: Why Teams Are Switching to Sentry

How To Get User Input in Java

The SolutionThe Solution

Further ReadingFurther Reading

The Solution

Further Reading