初学C＋＋，几个Dev编译错误，请各路高手指正！多谢！
#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),

[解决办法]
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;

[解决办法]
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