메소드

package method;

public class Computer {
	// Field
	// Constructor
	// Method
	
	int sum1(int[] values) {
		int sum = 0;
		for(int i=0; i<values.length; i++) {
			sum += values[i];
		}
		return sum;
	}
	
	int sum2(int ...values) {
		int sum = 0;
		for(int i=0; i<values.length; i++) {
			sum += values[i];
		}
		return sum;
	}
	
	
}
​

package method;

public class Calculator {
	// Field
	// Constructor
	// Method
	void powerOn() {
		System.out.println("전원을 킵니다");
	}
	
	int plus(int x, int y) {
		int result = x + y;
		return result; // 어떤 메소드가 실행을 하면서 최종값으로 이 결과값을 얻었다.
					   // 그것을 반환 해준다
	}
	
	double divide(int x, int y) {
		double result = (double)x / (double)y;
		return result;
	}
	
	void powerOf() {
		System.out.println("전원을 끕니다");
	}
	
		
}

package method;

public class Calculator_Ex {
	public static void main(String[] args) {
		
		Calculator myCalc = new Calculator();

		myCalc.powerOn();
		
		int result1 = myCalc.plus(5, 6);
		System.out.println("result1 :" + result1);
		
		byte x = 10;
		byte y = 4;
		double result2 = myCalc.divide(x, y);
		System.out.println("result2 :" + result2);
		
		myCalc.powerOf();
		
	}
}

package method;

public class Calculator2 {
	// Field
	// Constructor
	// Method
	
	int plus(int x, int y) {
		int result = x + y;
		return result;
	}

	double avg(int x, int y) {
		double sum = plus(x, y);
		double result = sum / 2;
		return result;
	}
	
	void execute() {
		double result = avg(7, 10);
		println("실행결과 : " + result);
	}
	
	void println(String massage) {
		System.out.println(massage);
	}
		
	
}

package method;

public class Calculator2_Ex {
	
	public static void main(String[] args) {
	
		Calculator2 myCalac = new Calculator2();
		myCalac.execute();
		
	}
}

package method;

public class Car {
	// Filed
	int gas;
	
	// Constructor
	
	// Method
	void setGas(int gas) {
		this.gas = gas;
	}
	
	boolean isLeftGas() {
		if(gas == 0) {
			System.out.println("gas가 없습니다.");
			return false;
		}
		System.out.println("gas가 있습니다.");
		return true;
		// gas가 0이 아니라면 return true로 실행이 종료됨
	}
	
	void run() {
		while(true) {
			if(gas > 0) {
				System.out.println("달립니다.(gas잔량:" + gas + ")");
				gas -= 1;
 		} else {
 			System.out.println("멈춥니다.(gas잔량:" + gas + ")");
 			return;
 		}
	}
  }
}

package method;

public class Car_Ex {
	public static void main(String[] args) {
		
		Car myCar = new Car();
		
		myCar.setGas(5);
		
		if(myCar.isLeftGas()) {
			System.out.println("gas를 주입할 필요가 없습니다.");
		}else {
			System.out.println("gas를 주입하세요");
		}
		
		boolean gasState = myCar.isLeftGas();	
		if(gasState) {
			System.out.println("출발합니다.");
			myCar.run();
		}
		
	
	}
}

package method;

public class Car2  {
	// Field
	int speed;
	
	// Constructor
	
	//Method
	int getSpeed() {
		return speed;
	}
	
	void keyTurnOn() {
		System.out.println("키를 돌립니다.");
	}
	
	void run() {
		for(int i = 0; i <= 50; i+=10) {
			speed = i;
			System.out.println("달립니다.(시속:" + speed + "km/h");
		}
	}
	
}

package method;

public class Car2__Ex {
	
	public static void main(String[] args) {
	
	Car2 myCar = new Car2();
	
	myCar.keyTurnOn();
	myCar.run();
	int speed = myCar.getSpeed();
	System.out.println("현재 속도.(시속:" + speed + "km/h");
	
	
	
  }
}

package method;

import javax.swing.plaf.synth.SynthSpinnerUI;

public class Computer_Ex {
	
	public static void main(String[] args) {
		Computer myCom = new Computer();

		int[] values1 = {1,2,3};
		
		int result1 = myCom.sum1(values1);
		System.out.println("result : " + result1);
	
		int result2 = myCom.sum1(new int[] {1,2,3,4,5});
		System.out.println("result2 : " + result2);
		
		int result3 = myCom.sum2(1, 2, 3);
		System.out.println("result3 : " + result3);
		
		int result4 = myCom.sum2(1, 2, 3, 4, 5);
		System.out.println("result4 : " + result4);
		
		
	}
}