通不过编译，找不出问题，请大家帮忙看看哪里错了！谢谢！

[34栋610]

#include<iostream.h>
#include<stdlib.h>

class Rational // 声明有理数类
{
private:
//以分子/分母形式定义一个有理数
long num, den;
//有理数标准化及分子分母最大公约数
void Standardize(void);
long gcd(long m , long n) const;

public:
// 用于整数->有理数， 实数->有理数转换的构造函数
Rational(long num = 0, long den = 1);
Rational(double x);
//有理数的输入、输出
friend istream& operator>>(istream& istr, Rational& x);
friend ostream& operator<<(ostream& ostr, const Rational& x);
//重载算术运算符
Rational operator+(Rational v) const;
Rational operator-(Rational v) const;
Rational operator*(Rational v) const;
Rational operator/(Rational v) const;
Rational operator-(void) const;
bool operator< (Rational v) const;
bool operator<=(Rational v) const;
bool operator> (Rational v) const;
bool operator>=(Rational v) const;
bool operator==(Rational v) const;
bool operator!=(Rational v) const;
// 重载转换运算符:有理数->实数
operator double(void) const;
// 查看分子、分母、化简
long GetNumerator(void) const;
long GetDenominator(void) const;
void Reduce(void);

};

void Rational::Standardize(void) //标准化
{
if(num > 0 && den > 0)
;
else( (num < 0 && den < 0) || (num > 0 && den <0 ) )
{ num = -num;
den = -den;
}
}

long Rational::gcd(long m , long n) const // 求最大公约数
{
long temp;
temp= m < n ? m : n;
long big;
for(int i=1; i<=temp; i++)
if( (m%i == 0) && (n%i ==0) )
big =i;
return big;
}

Rational::Rational(long p, long q): num(p), den(q) // 用于整数->有理数， 实数->有理数转换的构造函数
{
if(den == 0)
{
cerr<< "denominator is zero " << endl;
exit(1);
}
}
Rational::Rational(double x)
{
double val;
val = 10000000L * val;
num = long(val);
den = 10000000L;
Standardize();
}

istream& operator>>(istream& istr, Rational& x) //有理数的输入、输出
{
char c;
istr>> x.num >> c >> x.den;
x.Standardize();
return istr;
}
ostream& operator<<(ostream& ostr, const Rational& x)
{
ostream<< x.num << '/' << x.den ;
return ostr;
}

Rational Rational::operator+(Rational v) const //重载算术操作符
{
return (num * v.den + den * v.num, den * v.den);
}
Rational Rational::operator-(Rational v) const
{
return (num * v.den - den * v.num, den * v.den);
}
Rational Rational::operator*(Rational v) const
{
return (num * v.num, den * v.den);
}
Rational Rational::operator/(Rational v) const
{
return (num * v.den, den* v.num);
}
Rational Rational::operator-(void) const
{
return (- num, - den);
}

bool Rational::operator<(Rational v) const //重载关系元算符
{
return num * v.den < den * v.num;
}
bool Rational::operator<=(Rational v) const
{
return num * v.den <= den * v.num;
}
bool Rational::operator>(Rational v) const
{
return num * v.den > den * v.num;
}
bool Rational::operator>=(Rational v) const
{
return num * v.den >= den * v.num;
}
bool Rational::operator==(Rational v) const
{
return num * v.den == den * v.num;
}
bool Rational::operator!=(Rational v) const
{
return num * v.den != den * v.num;
}

Rational::operator double(void) const // 重载转换运算符:有理数->实数
{
return double(num)/den;
}

long Rational::GetNumerator(void) const // 查看分子、分母
{
return num;
}
long Rational::GetDenominator(void) const
{
return den;
}

void Rational::Reduce(void) //化简
{
int bigdivisor, tempnumerator;
tempnumerator = (num<0)?-num:num;
if(num = 0)
den = 1;
else
{
bigdivisor = gcd(tempnumerator, den);
if(bigdivisor > 1)
{
num /= bigdivisor;
den /= bigdivisor;
}
}
}


void main()
{
Rational A(3,4), B(2,4);
A = A + B;
cout<< A << endl;
}
出现如下错误：
error C2143: syntax error : missing ';' before '{'
error C2143: syntax error : missing ';' before '<<'
error C2143: syntax error : missing ';' before '<<'
执行 cl.exe 时出错.

[chuachua66]

class{}; 仁兄你是不是没有那个红色的分号。

[lee_鹿游原]

 ostream& operator<<( ostream& ostr, const Rational& x )
{
	ostr<<x.num<<'/'<< x.den;
	return ostr;
}

[旅客]

ostream<< x.num << '/' << x.den ; 这句错了，ostream是输出流的类名，应该是流对象

[疯狂的红豆]

ostream& operator<<(ostream& ostr, const Rational& x) { ostream<< x.num << '/' << x.den ; //笔误了吧，应该是ostr<<x.num<<'/'<<x.edn; return ostr; }