std::basic_string::compare
性病：基本[医]字符串：比较
| int compare( const basic_string& str ) const; | (1) | |
|---|---|---|
| int compare( size_type pos1, size_type count1, const basic_string& str ) const; | (2) | |
| | (3) | |
| int compare( size_type pos1, size_type count1, const basic_string& str, size_type pos2, size_type count2 ) const; | (until C++14) | |
| int compare( size_type pos1, size_type count1, const basic_string& str, size_type pos2, size_type count2 = npos ) const; | (since C++14) | |
| int compare( const CharT* s ) const; | (4) | |
| int compare( size_type pos1, size_type count1, const CharT* s ) const; | (5) | |
| int compare( size_type pos1, size_type count1, const CharT* s, size_type count2 ) const; | (6) | |
| int compare( std::basic_string_view<CharT, Traits> sv) const; | (7) | (since C++17) |
| int compare( size_type pos1, size_type count1, std::basic_string_view<CharT, Traits> sv) const; | (8) | (since C++17) |
| template < class T > int compare( size_type pos1, size_type count1, const T& t, size_type pos2, size_type count2 = npos) const; | (9) | (since C++17) |
比较两个字符序列。
1%29将此字符串与斯塔尔。首先，计算要比较的字符数，好像size_type rlen =std::min(size(), str.size()).然后通过调用比较Traits::compare(data(), str.data(), rlen).对于标准字符串，此函数执行逐个字符的字典比较。如果结果为0%28--到目前为止字符串等于%29，那么它们的大小比较如下：
| Condition | Result | Return value |
|---|---|---|
| Traits::compare(data, arg, rlen) < 0 | data is less than arg | <0 |
| Traits::compare(data, arg, rlen) == 0 | size(data) < size(arg) | data is less than arg |
| size(data) == size(arg) | data is equal to arg | 0 |
| size(data) > size(arg) | data is greater than arg | 0 |
| Traits::compare(data, arg, rlen) > 0 | data is greater than arg | 0 |
2%29比较a[pos1, pos1+count1)此字符串的子字符串为斯塔尔好像basic_string(*this, pos1, count1).compare(str)%28直到C++17%29compare(pos1, count1,std::basic_string_view<CharT, Traits>(str))%28自C++17%29
3%29比较a[pos1, pos1+count1)将此字符串的子字符串转换为子字符串。[pos2, pos2+count2)成斯塔尔好像basic_string(*this, pos1, count1).compare(basic_string(str, pos2, count2))%28直到C++17%29compare(pos1, count1,std::basic_string_view<CharT, Traits>(str), pos2, count2)%28自C++17%29
4%29将此字符串与以斯，好像compare(basic_string(s))
5%29比较a[pos1, pos1+count1)将此字符串的子字符串转换为以斯，好像basic_string(*this, pos, count1).compare(basic_string(s))
6%29比较a[pos1, pos1+count1)此字符串的子字符串到第一个字符串。count2所指向的第一个字符的字符数组中的字符。斯，好像basic_string(*this, pos, count1).compare(basic_string(s, count2)).%28注：s到s+count2可能包含空字符%29%29
7%29将此字符串与sv，与%281%29相似，但使用sv.size()和sv.data()而不是str.size()和str.data()
8%29比较a[pos1, pos1+count1)此字符串的子字符串为sv，好像std::basic_string_view<CharT, Traits>(data(), size()).substr(pos1, count1).compare(sv)
9%29名皈依者t到字符串视图sv好像std::basic_string_view<CharT, Traits> sv = t;，然后比较[pos1, pos1+count1)将此字符串的子字符串转换为子字符串。[pos2, pos2+count2)成sv好像std::basic_string_view<CharT, Traits>(data(), size()).substr(pos1, count1).compare(sv.substr(pos2, count2)。此重载只参与以下情况下的过载解决方案：std::is_convertible_v<const T&,std::basic_string_view<CharT, Traits>>是true和std::is_convertible_v<const T&, const CharT*>是false...
参数
| str | - | other string to compare to |
|---|---|---|
| s | - | pointer to the character string to compare to |
| count1 | - | number of characters of this string to compare |
| pos1 | - | position of the first character in this string to compare |
| count2 | - | number of characters of the given string to compare |
| pos2 | - | position of the first character of the given string to compare |
| sv | - | std::basic_string_view to compare to |
| t | - | object (convertible to std::basic_string_view) to compare to |
返回值
负值*this按字典顺序出现在参数指定的字符序列之前。
如果两个字符序列比较等效，则为零。
正值*this在参数指定的字符序列之后，按字典顺序显示。
例外
1%29
| (none) | (until C++11) |
|---|---|
| noexcept specification: noexcept | (since C++11) |
2-6%5月29日抛出由相应的basic_string建筑工人。
| 7) noexcept specification: noexcept | (since C++17) |
|---|
可能的实施
模板<类图，类特征，类异种>INTBASIC[医]字符串<图表，性状，异基因>：：比较%28 const std：：basic[医]String&s%29 Const no，{size除外[医]LHS型[医]SZ=尺寸%28%29；尺寸[医]RHS型[医]SZ=S.size%28%29；INT结果=性状[医]类型：比较%28data%28%29，s.data%28%29，std：：min%28 lhs[医]SZ，RHS[医]SZ%29%29；if%28结果%21=0%29返回结果；if%28 lhs[医]SZ<RHS[医]SZ%29返回-1；if%28 lhs[医]SZ>RHS[医]SZ%29返回1；返回0；}
*。
注记
对于不需要进行三方比较的情况，std::basic_string提供通常的关系算子%28<，，，<=，，，==，，，>，等...%29。
默认情况下，%28与默认值std::char_traits%29，此函数不对区域设置敏感.。见std::collate::compare用于区域识别的三向字符串比较。
例
另见
| operator==operator!=operator | lexicographically compares two strings (function template) |
|---|---|
| substr | returns a substring (public member function) |
| collate | defines lexicographical comparison and hashing of strings (class template) |
| strcoll | compares two strings in accordance to the current locale (function) |
| lexicographical_compare | returns true if one range is lexicographically less than another (function template) |
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