Java Scanner Class Flashcards

Questions and Answers

What code is used to create a new scanner object named scnr?

Scanner scnr = new Scanner(System.in);

How do you return the next value of type String using a scanner named scnr?

fullName = scnr.nextLine();

How do you return the next value of type int using a scanner named scnr?

age = scnr.nextInt();

What is the purpose of the Scanner class?

This class is used for simple keyboard input. Signup and view all the answers

What is System.in?

An InputStream typically connected to keyboard input of console programs. Signup and view all the answers

The '___' operator allocates memory (on the heap) for a new object and initializes the new object.

new Signup and view all the answers

What is next() used for in the Scanner class?

It is used for one word input. Signup and view all the answers

What is a collection of classes that have been given a name?

Package Signup and view all the answers

What code is used to start a class called first and declare the main method?

public class first { public static void main(String[] args) { Signup and view all the answers

What do you need to type to import the Scanner class?

import java.util.Scanner; Signup and view all the answers

Study Notes

Java Scanner Class Overview

Scanner scnr = new Scanner(System.in); initializes a new Scanner object named scnr for reading input from the console.
fullName = scnr.nextLine(); captures the next line of input as a String, storing it in the variable fullName.
age = scnr.nextInt(); retrieves the next integer input from the user and assigns it to the variable age.

Key Concepts

The Scanner class is a part of java.util package and it simplifies keyboard input handling in Java applications.
System.in serves as the standard input stream connected to the console, allowing interaction via keyboard input.
The operator new is used to create and instantiate new objects in Java, allocating memory on the heap for those objects.

Scanner Functionality

The next() method reads the next input token as a String, which is ideal for single word inputs, separating them based on whitespace.
A package in Java is a namespace that organizes a set of related classes and interfaces, facilitating code management.

Basic Structure

The snippet public class first { public static void main(String[] args) { illustrates the structure for defining a new class and the entry point of a Java program.
To utilize the Scanner class in a program, the statement import java.util.Scanner; must be included at the beginning of the code to import the required class.

Additional Information

A Scanner instance is necessary for scanning various types of input, including Strings, integers, and more, through specific methods provided by the class.
Understanding memory allocation and class structure is crucial for effective Java programming, particularly when working with input handling.

Description

Test your knowledge of the Java Scanner class with these flashcards. Each card covers important definitions and example usage of the Scanner methods to read various data types. Perfect for beginners looking to master input handling in Java!