Java Programming Basics

Questions and Answers

Rearrange the following code so that it forms a correct program that prints out the letter Q:

public class Q { public static void main(String[] a) { System.out.println("Q"); } }

Write a statement that prints Hello, world to the screen.

System.out.println("Hello, world");

Write a complete main method that prints Hello, world to the screen.

public static void main(String[] args) { System.out.println("Hello, world"); System.exit(0); }

Suppose your name was Alan Turing. Write a statement that would print your last name, followed by a comma, followed by a space and your first name.

System.out.println("Turing, Alan"); Signup and view all the answers

Suppose your name was George Gershwin. Write a complete main method that would print your last name, followed by a comma, followed by a space and your first name.

public static void main(String[] args) { System.out.println("Gershwin, George"); System.exit(0); } Signup and view all the answers

Write a complete program whose class name is Hello and that displays Hello, world on the screen.

public class Hello { public static void main(String[] args) { System.out.println("Hello, world"); System.exit(0); } } Signup and view all the answers

The rules that govern the correct order and usage of the elements of a language are called the _______ of the language.

syntax Signup and view all the answers

The standard name of the Java compiler is _______.

javac Signup and view all the answers

A compiler translates source code into _______.

executable code Signup and view all the answers

The import statement needed to use JOptionPane is _______.

import javax.swing.JOptionPane; Signup and view all the answers

Given an integer variable count, write a statement that displays the value of count on the screen.

System.out.println(count); Signup and view all the answers

Two variables, num and cost have been declared and given values. Write a single statement that outputs num and cost to standard output.

System.out.println(num + " " + cost + "\n"); Signup and view all the answers

Declare an integer variable named degreesCelsius.

int degreesCelsius; Signup and view all the answers

Declare two integer variables named profitStartOfQuarter and cashFlowEndOfYear.

int profitStartOfQuarter; int cashFlowEndOfYear; Signup and view all the answers

Study Notes

Java Program Structure

A basic Java program requires a class definition, typically starting with public class ClassName.
The main method is the entry point of the Java application: public static void main(String[] args).
To print output on the screen, use System.out.println("Your text").

Printing Statements

Use System.out.println("Hello, world") to print "Hello, world" to the screen.
To print custom text such as names, format using string concatenation: System.out.println("LastName, FirstName").

Compiler and Syntax

The Java compiler is called javac, which translates source code into executable code.
Syntax refers to the rules that dictate the correct structure and order of elements in the Java language.

Variable Declaration

Declare variables using the syntax: dataType variableName;.
Example declarations:
- int degreesCelsius; for an integer variable.
- Multiple variables can be declared in sequence: int profitStartOfQuarter; int cashFlowEndOfYear;.

Import Statements

Use import javax.swing.JOptionPane; to enable the use of the JOptionPane class for dialogue boxes in a Java program.

Output Formatting

To display multiple variables in a single line, use string concatenation: System.out.println(num + " " + cost);.
System.out.println(count); outputs the value of an integer variable count without any additional text.

Program Termination

Use System.exit(0); at the end of the main method to indicate successful termination of the program.

Description

Test your knowledge on basic Java programming concepts with these flashcards. The quiz includes exercises on printing statements and structuring a simple Java program. Perfect for beginners looking to solidify their understanding of Java syntax.