Java Scanner Class Flashcards

By default, the values read by Scanner input methods are delimited by spaces, tabs, and newline characters.

The next and nextLine methods both read and return character strings.

The Scanner class does not have a method to read a single character.

The nextLine method of the Scanner class consumes the newline character at the end of the line.

What package is the Scanner class a part of?

What is passed to the constructor when a new Scanner object is created?

What is the text used to request information from a user called?

What object represents the standard input stream, which is input typed by the user at the keyboard?

What happens if an input value does not match the type expected by the Scanner method used to read it?

Scanner Class Overview

By default, Scanner reads input values delimited by spaces, tabs, and newline characters, collectively known as white space.
The next and nextLine methods return character strings, but differ in the quantity of text they read: next reads a single word, while nextLine reads the entire line until a newline character is encountered.

Input Handling

The Scanner class does not provide a method to read individual characters directly; to achieve this, a string must be read first and processed one character at a time.
The nextLine method consumes the newline character at the end of the line, but the character itself is not included in the returned string.

Scanner Class Details

The Scanner class is part of the java.util package, which must be imported for use.
When creating a new Scanner object, the constructor takes the source of input as an argument, which can be anything from user input to file data.

User Interaction

The text used to prompt the user for information is called a prompt, guiding the user on what input is expected.
The standard input stream representing keyboard input is System.in, allowing Scanner to read data entered by the user.

Error Handling

If an input value does not match the expected type for the method used (e.g., reading a string as an integer), an exception will be thrown, indicating a mismatch or error in input handling.

Test your knowledge of the Java Scanner class with these flashcards! The questions cover key concepts such as input methods and string reading capabilities. Perfect for Java learners looking to reinforce their understanding.