21 Strings library [strings]

21.4 Class template basic_string [basic.string]

21.4.7 basic_string string operations [string.ops]

21.4.7.9 basic_string::compare [string::compare]

int compare(const basic_string& str) const noexcept;

Effects: Determines the effective length rlen of the strings to compare as the smallest of size() and str.size(). The function then compares the two strings by calling traits::compare(data(), str.data(), rlen).

Returns: The nonzero result if the result of the comparison is nonzero. Otherwise, returns a value as indicated in Table [tab:strings.compare].

Table 72compare() results
ConditionReturn Value
size() < str.size() < 0
size() == str.size() 0
size() > str.size() > 0

int compare(size_type pos1, size_type n1, const basic_string& str) const;

Returns: basic_string(*this,pos1,n1).compare(str).

int compare(size_type pos1, size_type n1, const basic_string& str, size_type pos2, size_type n2 ) const;

Returns: basic_string(*this, pos1, n1).compare(basic_string(str, pos2, n2)).

int compare(const charT *s) const;

Returns: compare(basic_string(s)).

int compare(size_type pos, size_type n1, const charT *s) const;

Returns: basic_string(*this, pos, n1).compare(basic_string(s)).

int compare(size_type pos, size_type n1, const charT *s, size_type n2) const;

Returns: basic_string(*this, pos, n1).compare(basic_string(s, n2)).