Standard Console Input: java.util.Scanner and System.out Formatting0%

if, if-else, and if-else-if Decision Ladders

Standard Console Input: java.util.Scanner and System.out Formatting

Beginner13 min read•Updated: 2026-10-22

⌨️ Standard Console Input with Scanner & Formatted Output

Introduction

Interactive console applications require reading user input from the keyboard. In Java, this is managed by the java.util.Scanner class, which parses primitives and strings using regular expressions.

📥 Reading Data with `Scanner`

1import java.util.Scanner;
2 
3public class UserInputDemo {
4    public static void main(String[] args) {
5        Scanner scanner = new Scanner(System.in);
6 
7        System.out.print("Enter Student Full Name: ");
8        String name = scanner.nextLine(); // Reads full text line including spaces
9 
10        System.out.print("Enter Age: ");
11        int age = scanner.nextInt();
12 
13        System.out.print("Enter Course Fee Paid: ₹");
14        double fee = scanner.nextDouble();
15 
16        System.out.println("\n--- Student Summary ---");
17        System.out.printf("Name : %s%n", name);
18        System.out.printf("Age  : %d years old%n", age);
19        System.out.printf("Fee  : ₹%,.2f%n", fee); // Formatted with comma separators and 2 decimals
20 
21        scanner.close(); // Clean up scanner resource
22    }
23}

⚠️ The Infamous `nextLine()` Skip Gotcha

When calling nextInt() or nextDouble(), Scanner consumes the number but leaves the trailing newline (\n) in the buffer. If you subsequently call nextLine(), it consumes that leftover newline immediately and appears to "skip" input!

Solution:

Consume the leftover newline with a blank scanner.nextLine() call before reading text:

1int age = scanner.nextInt();
2scanner.nextLine(); // Consume leftover newline character!
3String address = scanner.nextLine(); // Now reads text properly!

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if, if-else, and if-else-if Decision Ladders

Standard Console Input: java.util.Scanner and System.out Formatting

Beginner13 min read•Updated: 2026-10-22

Study Materials

⌨️ Standard Console Input with Scanner & Formatted Output

Introduction

📥 Reading Data with `Scanner`

1import java.util.Scanner;
2 
3public class UserInputDemo {
4    public static void main(String[] args) {
5        Scanner scanner = new Scanner(System.in);
6 
7        System.out.print("Enter Student Full Name: ");
8        String name = scanner.nextLine(); // Reads full text line including spaces
9 
10        System.out.print("Enter Age: ");
11        int age = scanner.nextInt();
12 
13        System.out.print("Enter Course Fee Paid: ₹");
14        double fee = scanner.nextDouble();
15 
16        System.out.println("\n--- Student Summary ---");
17        System.out.printf("Name : %s%n", name);
18        System.out.printf("Age  : %d years old%n", age);
19        System.out.printf("Fee  : ₹%,.2f%n", fee); // Formatted with comma separators and 2 decimals
20 
21        scanner.close(); // Clean up scanner resource
22    }
23}

⚠️ The Infamous `nextLine()` Skip Gotcha

Solution:

Consume the leftover newline with a blank scanner.nextLine() call before reading text:

1int age = scanner.nextInt();
2scanner.nextLine(); // Consume leftover newline character!
3String address = scanner.nextLine(); // Now reads text properly!

Next Lesson

if, if-else, and if-else-if Decision Ladders

Continue learning with hands-on practice, examples, and exercises in the upcoming topic.

Related Lessons

Previous Lesson	Next Lesson
Arithmetic, Assignment, Relational, and Logical Operators	if, if-else, and if-else-if Decision Ladders

Practice Quiz

Test your understanding of this lesson with 1 questions. Each question has one correct answer.

Previous Next

⌨️ Standard Console Input with Scanner & Formatted Output

Introduction

📥 Reading Data with Scanner

⚠️ The Infamous nextLine() Skip Gotcha

Solution:

if, if-else, and if-else-if Decision Ladders

Related Lessons

Practice Quiz

Loading Page Content...

⌨️ Standard Console Input with Scanner & Formatted Output

Introduction

📥 Reading Data with Scanner

⚠️ The Infamous nextLine() Skip Gotcha

Solution:

if, if-else, and if-else-if Decision Ladders

Related Lessons

Practice Quiz

📥 Reading Data with `Scanner`

⚠️ The Infamous `nextLine()` Skip Gotcha

📥 Reading Data with `Scanner`

⚠️ The Infamous `nextLine()` Skip Gotcha