新手求助：VC程序

[lanbingerfly]

#include<iostream.h>
#include<conio.h>
#include<math.h>
float area(float x,float y,float z);
int main()
{ float a,b,c,s;
cout<<"please input 3 sides of one triangle:"<<endl;
cin>>a>>b>>c>>endl;
cout<<a<<b<<c<<endl;
s=area(a,b,c);
cout<<"area of triangle is:"<<endl;
}
float area(float x,float y,float z)
{
float p,t;
p=(x+y+z)/2;
t=sqrt(p*(p-x)(p-y)(p-z));
return t;
}
这是一个求三角形面积的VC程序，编译时老出错，错误如下：Compiling...
liu.cpp
c:\program files\microsoft visual studio\myprojects\liu\liu.cpp(11) : error C2679: binary '>>' : no operator defined which takes a right-hand operand of type 'class ostream &(__cdecl *)(class ostream &)' (or there is no acceptable conversion)
c:\program files\microsoft visual studio\myprojects\liu\liu.cpp(17) : warning C4508: 'main' : function should return a value; 'void' return type assumed
c:\program files\microsoft visual studio\myprojects\liu\liu.cpp(24) : error C2064: term does not evaluate to a function
执行 cl.exe 时出错.

liu.obj - 1 error(s), 0 warning(s)
请问是什么原因？

[Eleven]

#include "stdafx.h"

#include<iostream>

#include<conio.h>
#include<math.h>
using namespace std;
float area(float x,float y,float z);

int main()
{ 
	float a,b,c,s; 
	cout<<"please input 3 sides of one triangle:"<<endl;
	cin>>a;
	cin>>b;
	cin>>c;
	if(a <=0 || b <=0 || c<=0)
	{
		cout<<"input error"<<endl;
		return -1;
	}
	cout<<a<<","<<b<<","<<c<<endl;
	s=area(a,b,c);
	cout<<"area of triangle is:"<<s<<endl;
	return 0;
}
float area(float x,float y,float z)
{
	float p,t;
	p=(x+y+z)/2;
	t=sqrt(p*(p-x)*(p-y)*(p-z));
	return t;
}

需要检查与一下，a，b，c是否为负数

[lanbingerfly]

[Quote=引用 2 楼 tandyt 的回复:]
cin>>a>>b>>c>>endl;

修改为 ：

cin>>a;
cin>>b;
cin>>c;
cout<<endl;
[/Quote]
我看很多代码中都这么连着写的。这样写不行吗?

[lanbingerfly]

[Quote=引用 6 楼 tandyt 的回复:]
完整的为：


C/C++ code

#include<iostream.h>
#include<conio.h>
#include<math.h>
float area(float x,float y,float z);
int main()
{ float a,b,c,s;
cout<<"please input 3 sides of one triangle:"<<……
[/Quote]编译时有更多的错误:Compiling...
liu.cpp
C:\Program Files\Microsoft Visual Studio\MyProjects\liu\liu.cpp(11) : error C2018: unknown character '0xa3'
C:\Program Files\Microsoft Visual Studio\MyProjects\liu\liu.cpp(11) : error C2018: unknown character '0xbb'
C:\Program Files\Microsoft Visual Studio\MyProjects\liu\liu.cpp(12) : error C2146: syntax error : missing ';' before identifier 'cin'
C:\Program Files\Microsoft Visual Studio\MyProjects\liu\liu.cpp(12) : error C2018: unknown character '0xa3'
C:\Program Files\Microsoft Visual Studio\MyProjects\liu\liu.cpp(12) : error C2018: unknown character '0xbb'
C:\Program Files\Microsoft Visual Studio\MyProjects\liu\liu.cpp(13) : error C2146: syntax error : missing ';' before identifier 'cin'
C:\Program Files\Microsoft Visual Studio\MyProjects\liu\liu.cpp(28) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
执行 cl.exe 时出错.

liu.obj - 1 error(s), 0 warning(s)
怎么回事？

[TandyT]

[Quote=引用 10 楼 lanbingerfly 的回复:]
引用 6 楼 tandyt 的回复:
完整的为：


C/C++ code

#include<iostream.h>
#include<conio.h>
#include<math.h>
float area(float x,float y,float z);
int main()
{ float a,b,c,s;
cout<<"please input 3 sides ……
[/Quote]

我这里编译没错的，是不是你复制时，复制了一些VC编译器不能识别的东西？你先存储到 记事本，然后再拷贝到 VC 里面编译试试

[斯巴达克斯]

“”里的东西是string型变量，不能直接用>>输入的，你得重载>>运算符才行

[TandyT]

cin>>a>>b>>c>>endl;

修改为 ：

cin>>a;
cin>>b;
cin>>c;
cout<<endl;

[pal513]

是不是少了 ( use namespace std; )？

[ywwj5858792qd]

1.using namespace std;
2.main 函数返回类型为void

[TandyT]

[Quote=引用 2 楼 tandyt 的回复:]
cin>>a>>b>>c>>endl;

修改为 ：

cin>>a;
cin>>b;
cin>>c;
cout<<endl;
[/Quote]

还有：

t=sqrt(p*(p-x)(p-y)(p-z));

改为：
t=sqrt(p*(p-x)*(p-y)*(p-z));

[TandyT]

完整的为：

#include<iostream.h>
#include<conio.h>
#include<math.h>
float area(float x,float y,float z);
int main()
{ float a,b,c,s; 
cout<<"please input 3 sides of one triangle:"<<endl;
cin>>a;
cin>>b;
cin>>c;
cout<<endl;
cout<<a<<b<<c<<endl;
s=area(a,b,c);
cout<<"area of triangle is:"<<endl;
return 0;
}
float area(float x,float y,float z)
{
	float p,t;
	p=(x+y+z)/2;
	t=sqrt(p*(p-x)*(p-y)*(p-z));
	return t;
}

[Dreadnought]

c:\program files\microsoft visual studio\myprojects\liu\liu.cpp(11) : error C2679: binary '>>' : no operator defined which takes a right-hand operand of type 'class ostream &(__cdecl *)(class ostream &)' (or there is no acceptable conversion) 你加入using namespace std; 或者std::cout std::com std::endl试试

c:\program files\microsoft visual studio\myprojects\liu\liu.cpp(17) : warning C4508: 'main' : function should return a value; 'void' return type assumed main函数应该返回个值,


c:\program files\microsoft visual studio\myprojects\liu\liu.cpp(24) : error C2064: term does not evaluate to a function 解决 error C2064 这种错误，关键是找到它所指向的错误行里面所有调用的函数名，他们中一定至少有一个是未被定义过的。

[lanbingerfly]

嗯，这次好了，谢了