# include<iostream.h>
# include<string.h>
class strings
{
public:
    strings(string a);
private:
    char contents[50];
    int length;
};
strings::strings(string a)
{
    int l;
    char s[6]="hallo";
    l=length(s);
    cout<<"The original string and length"<<endl;
    cout<<s<<"  "<<l<<endl;
    contents=s+a;
    length=strlen(contents);
    cout<<" now string and length"<<endl;
    cout<<contents<<"  "<<length<<endl;
}
void main()
{
    strings sd;
    string a;
    cout<<"please input a string"<<endl;
    cin>>a;
    sd(a);
}

收到的鲜花

• 寒风中的细雨 于 2012-11-27 20:33 送鲜花  1朵   附言：编译下就知道什么错了

#include<iostream>
#include<string>
using namespace std;
class strings
{
public:
    strings(string a);
private:
    char contents[50];
    int length;
};
strings::strings(string a)
{
    int l;
    char s[6]="hallo";
    l=strlen(s);       //方法应使用strlen()
    cout<<"The original string and length"<<endl;
    cout<<s<<"  "<<l<<endl;
    strcpy(contents,s);//字符串才可以直接用+的
    strcat(contents,a.c_str());
    length=strlen(contents);
    cout<<" now string and length"<<endl;
    cout<<contents<<"  "<<length<<endl;
}
void main()
{
   
    string a;
    cout<<"please input a string"<<endl;
    cin>>a;
     strings sd(a); //构造函数要有参数的
}

楼上正解

别的话不多说,我只想说,你是好人.....