Comments by boyhailong (Top 6 by date)

what you said is beneficial ，thanks！

i know ， i just write the whole class in a file

ok， sorry， i forge it 。
error C2440: “return”: can't transfer “const String”to “String &”

one is ：
String & String::operator=(const String & st)
{
if (this == &st)
return st;
delete [] str;
len = st.len;
return st;
}
error C2440: “return”: 无法从“const String”转换为“String &”