class Exercise8_1
{
public static void main(String[] args){
Triangle tr = new Triangle();
tr.setColor = "yellow";
tr.isFilled = true;
System.out.println(tr.toString());
}
}class Triangle extends GeometricObject {
double side1, side2, side3; /** Constructor */
public Triangle() {
} /** Implement the abstract method findArea in GeometricObject */
public double getArea() {
double s = (side1 + side2 + side3) / 2;
return Math.sqrt(s * (s - side1) * (s - side2) * (s - side3));
} /** Implement the abstract method findCircumference in
* GeometricObject
**/
public double getPerimeter() {
return side1 + side2 + side3;
}
/** Override the toString method */
public String toString() {
return "Triangle: side1 = " + side1 + " side2 = " + side2 +
" side3 = " + side3;
}
}// GeometricObject.java: The abstract GeometricObject class
class GeometricObject {
private String color = "white";
private boolean filled; /**Default construct*/
GeometricObject() {
} /**Getter method for color*/
public String getColor() {
return color;
} /**Setter method for color*/
public void setColor(String color1) {
color = color1;
} /**Getter method for filled. Since filled is boolean,
so, the get method name is isFilled*/
public boolean isFilled() {
return filled;
} /**Setter method for filled*/
public void setFilled(boolean filled1) {
filled = filled1;
}
}
---------- javac ----------
Exercise8_1.java:9: 错误: 找不到符号
tr.setColor = "yellow";
^
符号: 变量 setColor
位置: 类型为Triangle的变量 tr
Exercise8_1.java:10: 错误: 找不到符号
tr.isFilled = true;
^
符号: 变量 isFilled
位置: 类型为Triangle的变量 tr
2 个错误输出完成 (耗时 2 秒) - 正常终止
class Exercise8_1 {
public static void main(String[] args) {
Triangle tr = new Triangle();
tr.setColor ( "yellow");
tr.setFilled ( true);
System.out.println(tr.toString());
}
}class Triangle extends GeometricObject {
double side1, side2, side3; /** Constructor */
public Triangle() {
} /** Implement the abstract method findArea in GeometricObject */
public double getArea() {
double s = (side1 + side2 + side3) / 2;
return Math.sqrt(s * (s - side1) * (s - side2) * (s - side3));
} /** Implement the abstract method findCircumference in * GeometricObject **/
public double getPerimeter() {
return side1 + side2 + side3;
} /** Override the toString method */
public String toString() {
return "Triangle: side1 = " + side1 + " side2 = " + side2 + " side3 = "
+ side3;
}
} class GeometricObject {
private String color = "white";
private boolean filled; /** Default construct */
GeometricObject() {
} /** Getter method for color */
public String getColor() {
return color;
} /** Setter method for color */
public void setColor(String color1) {
color = color1;
} /**
* Getter method for filled. Since filled is boolean, so, the get method
* name is isFilled
*/
public boolean isFilled() {
return filled;
} /** Setter method for filled */
public void setFilled(boolean filled1) {
filled = filled1;
}
}