import javabook.*;
class Triangle
{
// DATA
//............................................................
//Private Variables
private double theBase;
private double theHeight;
private double theArea; //base and height = Area is enough calculation
// CONSTRUCTORS
//............................................................ // same name as the class and the file name
public Triangle()
{
this.theBase=0;
this.theHeight=0;
this.theArea=0;
}
public Triangle( OutputBox oBox, MainWindow mWindow )
{
this.theBase=0;
this.theHeight=0; this.theArea=0; //This is a proof that the area of any triangle is 1/2 b x h’ of a base and height and the ‘area of a triangle is half of the base times the height’.
}
public void calculateArea ()
{
InputBox iBox = new InputBox(mWindow);
this.theBase = iBox.getDouble("Please enter the length of the base of the triangle ");
this.theHeight = iBox.getDouble("Please enter the height of the triangle");
computeArea();
oBox.println(" The area of a triangle of base : " + this.theBase+ " and height : " + this.theHeight +" is equal to : "+ this.theArea );
}
// METHODS - behaviours
//............................................................
public void computeArea()
{
this.theArea = (this.theBase / 2 ) * this.theHeight;
}
// METHODS - gets (accessors) and sets (mutators)
//............................................................
//length
public void setThebase(double base)
{
this.theBase= base;
}
public double getTheBase()
{
return(this.theBase);
}
//breath
public void setTheHeight(double height)
{
this.theHeight= height;
}
public double getTheHeight()
{
return(this.theHeight);
}
//area
public double getTheArea()
{
return(this.theArea);
}
}
我在 this.theBase = iBox.getDouble（“请输入三角形底边的长度”）之上或之上缺少一些东西; 任何人都可以指出它取决于我的'我把它留了出来？因为我正在学习java并且一定会犯错误，所以请保持温和。
修复伪造{character：
后，这是修改后的错误消息]./Triangle.java:42: cannot find symbol
symbol : variable mWindow
location: class Triangle
InputBox iBox = new InputBox(mWindow);
^
./Triangle.java:46: cannot find symbol
symbol : variable oBox
location: class Triangle
oBox.println(" The area of a triangle of base : " + this.theBase+ " and height : " + this.theHeight +" is equal to : "+ this.theArea );
更新了4个错误：
./Triangle.java:36: cannot find symbol
symbol : variable oBox
location: class Triangle
this.oBox = oBox;
^
./Triangle.java:37: cannot find symbol
symbol : variable mWindow
location: class Triangle
this.mWindow = mWindow; //This is a proof that the area of any triangle is 1/2 b x h’ of a base and height and the ‘area of a triangle is half of the base times the height’.
^
./Triangle.java:47: cannot find symbol
symbol : variable mwindow
location: class Triangle
InputBox iBox = new InputBox(mwindow);
^
./Triangle.java:51: cannot find symbol
symbol : variable oBox
location: class Triangle
oBox.println(" The area of a triangle of base : " + this.theBase+ " and height : " + this.theHeight +" is equal to : "+ this.theArea );
^
Note: App.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
4 errors
^
答案 0 :(得分：3)
第一个}之后的所有代码都不属于某个方法，因此......您需要创建一个代码。像这样：
public Triangle( OutputBox oBox, MainWindow mWindow ) {
this.theBase=0;
this.theHeight=0
this.theArea=0;
}
public void calculateArea() {
InputBox iBox = new InputBox(mWindow);
this.theBase = iBox.getDouble("Please enter the length of the base of the triangle ");
this.theHeight = iBox.getDouble("Please enter the height of the triangle");
computeArea();
oBox.println(" The area of a triangle of base : " + this.theBase+ " and height : " + this.theHeight +" is equal to : "+ this.theArea );
}
}
然后，您可以在制作calculateArea()对象后致电Triangle。
如果您有任何问题或疑问，请与我们联系。
关于您的其他错误，原因是您没有存储mWindow和oBox的值。变化：
public Triangle( OutputBox oBox, MainWindow mWindow )
{
this.theBase=0;
this.theHeight=0;
this.theArea=0;
//This is a proof that the area of any triangle is 1/2 b x h’ of a base and height and the ‘area of a triangle is half of the base times the height’.
}
到
public Triangle( OutputBox oBox, MainWindow mWindow )
{
this.theBase=0;
this.theHeight=0;
this.theArea=0;
this.oBox = oBox;
this.mWindow = mWindow;
//This is a proof that the area of any triangle is 1/2 b x h’ of a base and height and the ‘area of a triangle is half of the base times the height’.
}
并使用您的私有变量添加oBox和mWindow。
请注意，如果未使用上面的构造函数，您将收到运行时错误。
import javabook.*;
class Triangle
{
// DATA
//............................................................
//Private Variables
private double theBase;
private double theHeight;
private double theArea; //base and height = Area is enough calculation
private OutputBox oBox;
private MainWindow mWindow;
// CONSTRUCTORS
//............................................................ // same name as the class and the file name
public Triangle( OutputBox oBox, MainWindow mWindow )
{
this.theBase=0;
this.theHeight=0;
this.theArea=0; //This is a proof that the area of any triangle is 1/2 b x h’ of a base and height and the ‘area of a triangle is half of the base times the height’.
this.oBox = oBox;
this.mWindow = mWindow;
}
public void calculateArea ()
{
InputBox iBox = new InputBox(this.mWindow);
this.theBase = iBox.getDouble("Please enter the length of the base of the triangle ");
this.theHeight = iBox.getDouble("Please enter the height of the triangle");
computeArea();
this.oBox.println(" The area of a triangle of base : " + this.theBase+ " and height : " + this.theHeight +" is equal to : "+ this.theArea );
}
// METHODS - behaviours
//............................................................
public void computeArea()
{
this.theArea = (this.theBase / 2 ) * this.theHeight;
}
// METHODS - gets (accessors) and sets (mutators)
//............................................................
//length
public void setThebase(double base)
{
this.theBase = base;
}
public double getTheBase()
{
return(this.theBase);
}
//breath
public void setTheHeight(double height)
{
this.theHeight= height;
}
public double getTheHeight()
{
return(this.theHeight);
}
//area
public double getTheArea()
{
return(this.theArea);
}
}