Java Basics

In this lesson, you will learn about Java history, the types of Java programs, and what Java editions exist today. History Sun Microsystems Inc developed Java in 1991 by the Green Team, whose members were James Gosling, Mike Sheridan, and Patrick Naughton. First, it was developed as a pilot project of a simple language for programming smart home…

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class Test { public void print(String word) { System.out.println(word); } } class Test2 { public void callPrintMethod() { Test test = new Test(); test.print(“Hello”); } } class Test { public static void print(String word) { System.out.println(word); } public static void main(String[] args) { print(“Hello!”); // OK Test.print(“Hello!”); // OK } } class Test2 { public…

Read More Java Instance and Static Methods

public void methodName() { // code to be executed } public void methodName(int num, String data) { // code to be executed } methodName() methodName(10, “dataString”); class Test { public int sumNumbers(int a, int b) { int sum = a + b; return sum; } public static void main(String[] args) { int num1 = 10;…

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type variableName = variableValue; public class Car { String brand; int maxSpeed; } class Car { String brand; int maxSpeed; public void printFields() { System.out.println(“BRAND: ” + brand); System.out.println(“MAX SPEED: ” + maxSpeed); } } public class Test { public static void main(String[] args) { Car ford = new Car(); ford.brand = “Ford”; ford.maxSpeed =…

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class Car { int numberOfSeats = 4; void addOneSeat(int numberOfSeats) { numberOfSeats = numberOfSeats + 1; // changes will only affect the local variable } public static void main(String args[]) { Car car = new Car(); System.out.println(“Number of seats before the change: ” + car.numberOfSeats); car.addOneSeat(car.numberOfSeats); System.out.println(“Number of seats after the change ” + car.numberOfSeats);…

Read More Java Pass-by-Value vs Pass-by-Reference

byte Uses 1 byte (8 bits) for a binary record of integers Values ​​of this type are integers in the range -2 ^ 7 to 2 ^ 7-1, ie. [-128, 127] The default value is 0 Example: byte var1=120, byte var2=-30 short Uses 2 bytes (16 bits) to write integer binaries Values ​​of this type…

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Operator Description Example + Indicates positive value +a – Negates an expression value (Converts positive number to negative) -a ++ Increments a value by 1 ++a — Decrements a value by 1 –a ! Inverts the value of a boolean type !true gives false %= Assigns the remainder to the left operand when dividing the…

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public class App { public static void main(String[] args) { // … } } public class App { public static void main(String[] args) { for(String s : args) { System.out.println(s); } } } public static void main(String[] args) public static void main(String []args)  public static void main(String args[]) public static void main(String… args) static public void main(String[] args) public static final void main(String[] args) final public static void main(String[] args)

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