Object Oriented Programming with Java: Complete beginners

Learn to output text in Java using System.out.println and print, concatenate strings with the plus operator, print expressions and variables, and control line breaks.

Declare and store integers in Java by declaring the type, such as int, assign a value, and print it with System.out.println, as shown with five plus six.

Learn to store decimal values in Java by using float and double variables, declare their types before values, and understand that floats hold smaller numbers while doubles hold larger ones.

Create string variables to store text and concatenate them with a space to print Hello world. Also define boolean variables to store true or false.

Learn how to use the if-else statement in Java to conditionally execute code based on numeric comparisons between two integers, printing appropriate messages for true or false outcomes.

Learn how else if statements extend the if logic in Java by adding multiple conditions. See how only one message prints, covering greater than, equal to, or the default case.

Learn how arrays in java store lists of one data type, and master the declaration syntax: type[], name, equals new type[length], for example with strings or integers.

Learn how to count index values in an array using zero-based indexing, with examples like watermelon, cherry, and banana.

Assign values to an array by index using zero-based indexing, placing dolphin, cat, dog, and elephant in order. Show that adding a fifth value requires increasing the array size.

Learn to declare and assign arrays in Java, print contents with Arrays.toString, sort with Arrays.sort, and check the array length.

Learn how to reassign values in Java arrays by updating an element at a specific index, changing 8 to 10 in even nums array to yield 2, 4, 6, 10.

Learn how to use for loops in Java to repeat statements, print hello world five times, and control iteration with initialization, condition, and update.

Iterate through an array with a for loop to print each element on its own line, using i from 0 to age.length and printing age[i].

Explore how object oriented programming in Java uses classes, objects, and methods, with objects defined by identity, state, and behavior, to create and interact with code.

Explore how object oriented programming uses classes as blueprints for objects. Create a Java class with name, breed, age, and color attributes using IntelliJ.

Learn how constructors create objects from a class and initialize attributes using parameters, including empty constructors, parallel variable names, and multiple-parameter examples like a dog class.

Create an object from a class using the new keyword, naming the object, and passing constructor parameters such as name, breed, age, and color.

Introduce methods in Java: a block of code inside a class that runs when called to reuse actions, access or mutate an object's state, and cover constructors and main method.

Explore Java method syntax by building public methods with void and return types, understanding return keywords, method headers, parameters, and the method body.

Define public accessor methods in a dog class to return object's data, such as get name and get breed, showing how to return a name or breed from dog object.

Create and use mutator methods to change an object's state, such as increasing a dog's age, using void return types and parameters, and verify with an accessor method.

Learn to take user input in Java with the scanner class from java.util, reading numbers with nextByte and strings with nextLine, and printing age messages.

Understand how public and private keywords control access to methods and instance variables. Use private to restrict access within a class, and remember private methods relate to inheritance later.

Explore how Java allows methods with the same name when their parameter lists differ. Learn to differentiate by parameter data types, order, and number of parameters.

Explore overloaded constructors in Java, including a no-parameter version, and how constructors with different parameter lists (same class name) initialize objects with default values.