2023-02-01 수 / JAVA

1. 아래가 돌아가도록 하시오.

main(){
    	Circle[] circleArr = new Circle[2];
    	circleArr[0] = new Circle(10);
    	circleArr[1] = new Circle(10);
    	    	
    	double areas = Circle.getArrArea(circleArr);
    	System.out.println(areas);
}

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class Circle {
	private double radius;

	Circle(double radius) {
		this.radius = radius;
	}

	double getArea() {
		return Math.PI * radius * radius;
	}

	public static double getArrArea(Circle[] circleArr) {
		double areas = 0;

		for (int i = 0; i < circleArr.length; i++) {
			areas += circleArr[i].getArea();
		}
		return areas;
	}
}

2. 아래가 18이 나오도록 getStrArr 함수를 만드시오.

    	String[] strArr = new String[3];
    	
    	strArr[0] = "ABCDER";
    	strArr[1] = "ABCDER";
    	strArr[2] = "ABCDER";
    	
    	System.out.println(getStrArr(strArr));

---

	public static int getStrArr(String[] strArr) {
		int cnum = 0;
		for (int i = 0; i < strArr.length; i++)
			cnum += strArr[i].length();

		return cnum;

3. 아래가 나오도록 Rectangle 객체를 만드시오.

    	Rectangle[] recArr = new Rectangle[2];
    	recArr[0] = new Rectangle(10,20);
    	recArr[1] = new Rectangle(10,30);

   	    	
    	areas = Rectangle.getArrArea(recArr);
    	System.out.println(areas);

---

class Rectangle {
	private int w, h;

	Rectangle(int w, int h) {
		this.w = w;
		this.h = h;
	}

	int getArea() {
		return w * h;
	}

	public static int getArrArea(Rectangle[] recArr) {
		int areas = 0;

		for (int i = 0; i < recArr.length; i++) {
			areas += recArr[i].getArea();
		}
		return areas;
	}
}

4. main 에서 실행된 Box[] ar = new Box[3] 대한 메모리 그림을 그리시오.

class Box {
   private String conts;
   
   Box(String cont) { 
   this.conts = cont; 
   }
   public String toString() {
      return conts;
   }
}

public static void main(String[] args) {
   Box[] ar = new Box[3];

   // 배열에 인스턴스 저장
   ar[0] = new Box("First");
   ar[1] = new Box("Second");
   ar[2] = new Box("Third");

   // 저장된 인스턴스의 참조
   System.out.println(ar[0]);
   System.out.println(ar[1]);
   System.out.println(ar[2]);
}

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