初学C＋＋，几个Dev编译错误，请各路高手指正！多谢！

[youxia001]

#include <iostream>

using namespace std;

class MyString
{
public:

static char * GetStringByLocation(char * srcStr,int startL,int endL)
{
//if(startL<endL || startL<0)
//{
// return null;
///}
int i=0;
char * resultStr=new char[endL-startL+1];
while(*srcStr!='\0')
{
if(i>=startL && i<=endL)
{
*resultStr++=*srcStr++;
}
else
{
srcStr++;
}
i++;
}
return resultStr;
}
static void StrCmp(char * toStr, char * fromStr)
{
int strLength=GetStrLength(fromStr);
toStr=new char[strLength];
while(*fromStr!='\0')
{
*toStr++=*fromStr++;
}
}
static char *ConvertStr(char * str)
{
int strLength=GetStrLength(str);
char * convert=new char[strLength];
for(int i=0;i<strLength;i++)
{
*convert++=*(str+(--strLength));
}
return convert;
}
static int GetStrLength(char * str)
{
int i=0;
while(str!='\0')
{
str++;
i++;
}
return i;
}
};

int main()
{
char * myStr="Hello World!";
char * resultStr= Mystring.GetStringByLocation(myStr,0,4);//65行
cout<<"截取以后的字符串:"<*resultStr;
cin.get();
//return 0;
}

编译错误如下：
String.cpp: In function `int main()':
String.cpp:65: error: `Mystring' undeclared (first use this function)
String.cpp:65: error: (Each undeclared identifier is reported only once for each function it appears
String.cpp:66: error: no match for 'operator<' in 'std::operator<<(std::basic_ostream<char, _Traits>&, const char*) [with _Traits = std::char_traits<char>]((&std::cout),

[mymtom]

char * resultStr= Mystring.GetStringByLocation(myStr,0,4);//65行
编译错误, 改为
char * resultStr= MyString::GetStringByLocation(myStr,0,4);//65行

cout<<"截取以后的字符串:"<*resultStr; // 66 行
改为
cout<<"截取以后的字符串:"<< resultStr;

[hellox]

Mystring.GetStringByLocation(myStr,0,4);//class MyString
cout<<"截取以后的字符串:"<*resultStr;//"<<*resultStr;

[hellox]

MyString.GetStringByLocation(myStr,0,4);
是不行的。。。
LZ是JAVA转C++的吧。。。？？看着有点像。。
先建个MyString的对象。。

[chenyu2202863]

String.cpp:65: error: `Mystring' undeclared (first use this function)============〉
你的类名字是MyString,而你写的却是Mystring,当然就说你没声明


cout<<"截取以后的字符串:"<*resultStr;==============〉
这里你写的是'<'而不是用的'<<',当然就没有重载了

[youxia001]

mymtom() 你好！65行给成 MyString::GetStringByLocation还是报错（这样应该是定义吧）
66行已解决！

用hellox(吃吃饭)方法也不行：
是这样写吗：
Mystring mystring=new Mystring();
char * resultStr= mystring.GetStringByLocation(myStr,0,4);