As a programming language with its fair share of quirks, one of the many things a new Java programmer will run into is the issue of their Scanner.nextLine() calls being ignored. Consider the following Java code:
JavaNextLineProblem.java
import java.util.Scanner;
public class JavaNextLineProblem {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
// Prompt the user to enter their name.
System.out.print("Enter your name: ");
String name = input.nextLine();
// Prompt the user to enter their age.
System.out.print("Enter your age: ");
int age = input.nextInt();
// Prompt the user to enter a description.
System.out.print("Describe yourself in a sentence: ");
String description = input.nextLine();
// Prompt the user to enter a message.
System.out.print("Enter a message: ");
String message = input.nextLine();
}
}
This is the desired result (user input coloured in green):
Enter your name: John Enter your age: 21 Describe yourself in a sentence: I am awesome. Enter a message: Hello world!
However, this is what you actually get:
Enter your name: John Enter your age: 21 Describe yourself in a sentence: Enter a message: Hello world!
The program skips over the collection of input for the Describe yourself in a sentence prompt, and goes straight into collecting the input for the Enter a message prompt. What’s going on?
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