Pluralsight - Java Fundamentals - The Java Language

[Heidel]

Паттерны
https://www.tutorialspoint.com/design_pattern/

Отредактировать переменные среды
Path C:\Program Files\Java\jre-10.0.2\bin

C:\Users\tfomina\IdeaProjects\ThirdProject\out\production\ThirdProject>java -version

Запустить программу из консоли
C:\Users\tfomina\IdeaProjects\ThirdProject\out\production\ThirdProject>java Main

Объявление массива

float[] theVals = new float[3];
float[] theVals = { 10.0f, 20.0f, 15.0f }; // то же самое

For-each Loop

for (loop-variable-declaration: array) 
	statement;

Пример

float[] theVals = { 10.0f, 20.0f, 15.0f };
float sum = 0.0f;
for( float currentVal: theVals )
	sum += currentVal;

Установка initial state в классе - 3 способа
- Field initializer
- Constructors
- Initialization blocks

Field Initial State
Поля получают "нулевое" значение по умолчанию

Конструкторы

public class Passenger {
	public Passenger() {
		
	}
	
	public Passenger(int freeBags) {
		this(freeBags > 1 ? 25.0d : 50.0d);
		this.freeBags = freeBags;
	}
	
	public Passenger(int freeBags, int checkedBags) {
		this(freeBags);
		this.checkedBags = checkedBags;
	}
	
	private Passenger(double perBagFee) {
		this.perBagFee = perBagFee;
	}
}

Initialization Block

public class Flight {
	private int passengers, flightNumber, seats = 150;
	private char flightClass;
	private boolean[] isSeatAvailable;
	
	// Initialization Block
	{
		isSeatAvailable = new boolean[seats];
		
		for(int i = 0; i < seats; i++) {
			isSeatAvailable[i] = true;
		}
	}
	
	public Flight() {}
	public Flight(int flightNumber) {
		this.flightNumber = flightNumber;
	}
	
	public Flight(char flightClass) {
		this.flightClass = flightClass;
	}
}

@темы: Java