Several problems of C + + string

The Find function of 1.string

Lookup (Find)

Grammar:

Size_type Find (const basic_string &STR, size_type index);

Size_type Find (const char *STR, size_type index);

Size_type Find (const char *STR, size_type index, size_type length);

Size_type Find (char ch, size_type index);

The Find () function:

Returns the position of the first occurrence of STR in the string, starting with index. If not found, return to String::npos,

Returns the position of the first occurrence of STR in the string, starting with index and length. If you don't find it, return to String::npos.

Returns the position of the first occurrence of the character ch in the string (found from index). If you don't find it, return to String::npos .

Several problems of C + + string