Become a Java Programmer

Explore how variables act as containers that store data, and learn the nine data types—int, byte, short, long, float, double, boolean, char, and string.

Learn how the integer data type stores whole numbers in Java using JShell, perform arithmetic with i and j, compare with ==, and note that Integer.MAX_VALUE is about 2 billion.

Explore the byte, short, and long data types for storing whole numbers and their differing storage sizes. Learn why long handles large values, and review Byte.MAX_VALUE and Short.MAX_VALUE.

Explore the float and double data types for decimals. Float uses four bytes, double eight, use the f suffix to distinguish, and doubles cannot convert to int; preferred for values.

Explore the boolean data type, its true and false values, and the case-sensitive, all-lowercase rule, with practical examples like boolean isValid = true and using booleans in expressions.

Learn the character data type, used to store a single character and is case sensitive. Declare chars with quotes, print them, and assign by integer values in JShell.

Explore the string data type in Java, learn to store and print text with System.out.println and Hello World, and convert integers to strings with Integer.toString in JShell.

Learn to name variables in Java using camel case, avoiding spaces, with examples like numberOfItems and firstName; understand how lowercase first word and capitalized subsequent words improve code validity.

Convert variables between data types by using casting for numbers and using toString methods for strings, as shown with int, double, long, boolean, and char conversions.

Review variables and data types in Java, including primitives int, byte, short, long, float, double, boolean, char, String, and learn camelCase naming, basic arithmetic, comparisons, and type conversion.

Install Eclipse and begin programming, exploring methods and classes as essential parts of a Java program, and examining method parameters, overloaded methods, comments, and return types.

Install Eclipse by downloading the Eclipse IDE for Java developers from eclipse.org, running the installer, and launching the workspace-ready application.

Create a class as a template and instantiate objects with new, as Fruit apple = new Fruit(); then use == to show identity versus equality among objects.

Learn to create and call methods in Java with jshell, using void, a method name, empty parentheses, and braces, and edit methods with /edit to print Hello World.

Explore method parameters in Java by defining methods with input values and passing arguments, such as multiplyNumbers with two doubles and printStrings with strings, and test in JShell.

Create your first Eclipse Java project by naming it FirstJavaProject, finish setup, and skip module creation, then create a new class named FirstClass for your code.

Create your first Eclipse Java project, add a class with a main method, print variables using System.out, and explore the package structure and run options.

Create a Car class with a main method and speed, save it as Car.java in JShell, then compile with javac Car.java and run with java Car to print 200.

Explore method overloading by showing addNumbers with two integers, three integers, two doubles, and two strings, and running them from a main method in a Java application.

Learn practical methods in JShell to streamline printing by creating a public void print with a string parameter that calls System.out.println, and overload print for integers.

Explore return types in Java, distinguishing void from int, string, and double returns, and learn how to print returned values with System.out.println.

Learn to use Java comments to document code and guide readers. Use // for single-line comments and /* ... */ for multi-line comments, closing them properly.

Review key Java concepts in the Eclipse IDE, including classes and objects, methods and parameters, overloaded methods, return types, and comments, with a quick recap of section 3.

Explore object oriented programming in Java, focusing on objects, encapsulation, constructors, inheritance, and modifiers in this section.

Create a new Java project in Eclipse, define a Person class with name and age fields, and add a printName method that prints the name to the console.

Encapsulation hides fields by making them private to prevent external modification. Expose access through public getters and setters for values like name and age, as shown with the Person class.

Learn encapsulation by creating an Aeroplane class with private speed, length, wingspan, and corresponding getters, setters, plus takeOff and land, demonstrated through AeroplaneRunner.

Constructors in Java are special methods that run automatically when creating objects, featuring default and parameterized forms to enforce required fields like name, age, and email, with getters and setters.

Create a country class with name, capitalCity, and population, provide getters and setters, and implement a constructor that makes the name field required.

Learn how the toString method prints a Person's name, age, and email, formats the output with String.format, and extends to include Employee’s companyName, employeeTitle, and phoneNumber.

Explore inheritance in Java by extending a superclass to reuse fields and methods, using super constructors, and adding subclass fields and getters and setters.

Practice inheritance by creating a vehicle class with color and speed and a start method, then extend it with a truck class that inherits these fields and behaviors.

Explore Java modifiers, including public, private, and protected access, and the final and static modifiers, with examples showing how protection levels affect visibility, initialization requirements, and static access.

Review section four of object oriented programming in Java, covering objects, encapsulation, constructors, inheritance, and modifiers such as public, private, protected, static, and final.

Explore conditionals that check whether a condition is true or false in Java. Learn about the if statement and the sweet statement as the section introduces these basics.

Test the if statement in JShell and Eclipse to see how conditions control output using comparisons, booleans, and the modulus operator.

Learn how to use if statements in Java to evaluate multiple conditions with and and or operators, employing ampersand and vertical bars, and explore true, false, and else if concepts.

Understand how the else if statement extends if logic, using examples with integers and strings, and employ modulus to test divisibility and string equality with dot equals.

Explore nested if statements by placing one if inside another, using two integers to demonstrate checks for ten and ten, with else handling using the and operator.

Practice five if statement exercises in Java, predicting outputs for booleans, modulus checks, string equality with case sensitivity, and dead code identification.

Explore the switch statement as a conditional that checks a variable's value with cases, includes breaks to prevent fall-through, and uses a default for unmatched values.

Switch on a day string in Eclipse. Create a class with a main method and a static method to handle Monday through Sunday, including a default invalid value.

Explore three switch statement exercises in a Java program. See how i and string cases determine outputs, and how missing break statements cause fall-through.

Learn how conditionals in Java work, using if and switch statements, with else if, else, nested conditionals, default case, and break to exit the switch.

Explore loops in this section of Become a Java Programmer, focusing on the full loop and the while loop that run code multiple times.

Becoming a Java programmer: this lecture shows for loops, starting value, i <= 20, and increments like i++ or i += 1 to print 0 to 20.

Build a multiplication table program in Java using a for loop from 1 to 12, formatting output with printf, and organizing with a runner class and a multiplication table class.

Explore while loop in Java and how it differs from for loop. See it print numbers 1 to 19 with increments, and use break to exit when conditions are met.

Build a simple digital clock in Java by using a while loop, local time now, and time unit sleep to print hours, minutes, and seconds every second.

Explore how the do while loop in Java executes at least once, a variant of the while loop, demonstrated by printing even numbers from 1 to 20.

Review section six on loops to understand how while, for, and do while loops operate in Java, including break statements and cases where loops run forever.

Explore how to import Java code and practice by building two projects: a rock-paper-scissors game and a text-based calculator.

Learn how to import the java.util Scanner class, optionally import all with asterisk, verify imports with set imports, and create a Scanner object with System.in in a sample Eclipse project.

Import the java.util.Random class, create a Random object, and generate random integers with nextInt(bound), noting that the bound is exclusive and can produce values up to bound-1.

Learn to use the Java scanner class to scan a username, a password, and a number, using next, nextLine, and nextInt to parse strings and integers.

Create a rock paper scissors game in Java by prompting user input with a scanner, generating a random computer choice with Random, and preparing to compare outcomes.

Learn to implement winner logic for a Java rock paper scissors game using if statements, covering draws, player and computer wins, invalid input handling, and user feedback.

Create a text-based calculator in Java using a single class with a main method, read two numbers with Scanner, prompt for an operation, and display the result.

Continue the calculator project by using doubles for numbers, reading an operation via a switch for add, subtract, multiply, and divide, and adding a do-while loop for repeated calculations.

Review section seven on imports and projects, covering package imports, scanner usage for strings and numbers, random integer generation, the rock paper scissors and calculator project, Java terms, and quiz.

Explore arrays and array lists in Java, learning how they store lists of items such as data types or objects, and examine the differences between the two structures.

This video introduces arrays in Java as lists stored in variables, and shows an integer array test scores and a string array days of week.

Learn to view and replace items at specific indices in arrays, using zero-based indexing with days of week and practice creating and updating a float array for monthly profits.

Discover how to get an array’s length with dot length and sort arrays with the Arrays sort method, including numeric profits and alphabetic string orders in a new copy.

Learn to loop through arrays in Java and print all items using a traditional for loop, and the enhanced for loop, avoiding index errors with proper bounds.

Learn how array lists differ from arrays, enable type safety with generics, and create and populate typed ArrayList instances using import, add, and wrapper classes for primitives.

Learn how to use key ArrayList methods—add, get, set, remove, size, and clear—through a five-item list, including replacing Nissan with Volvo and removing Toyota.

Sort an array list of doubles with the collections class, then loop through the list with a for loop to print each price after adding values.

Compare arrays and array lists to decide which to use in Java, noting that arrays have fixed size and can store primitives, while ArrayList is dynamic and holds only objects.

Create and compare arrays and array lists of employee objects in eclipse, using the add method to grow an array list while noting that arrays cannot change size.

Review arrays and array lists: arrays store primitives or objects and use length; array lists hold objects with wrapper classes and methods add, get, set, remove, size.

Learn how to handle exceptions in Java, addressing errors a driver program may encounter while running, and explore several ways to manage these issues for reliable programs.

Explore what exception is in Java and how it differs from syntax and compilation errors. See how input mismatch exception arises when a string is entered instead of a number.

Handle exceptions in a Java calculator program using try and catch blocks to validate numeric input, display an invalid input message, and re-prompt the user for correct numbers.