std::string replace() 方法

自 C++20 起

// (1) Non const version only
constexpr basic_string& replace( size_type pos, size_type count,
                       const basic_string& str );

// (1) Non const version only
constexpr basic_string& replace( const_iterator first, const_iterator last,
                       const basic_string& str );

// (2) Non const version only
constexpr basic_string& replace( size_type pos, size_type count,
                       const basic_string& str,
                       size_type pos2, size_type count2 = npos );


// (3) Non const version only
template< class InputIt >
constexpr basic_string& replace( const_iterator first, const_iterator last,
                                 InputIt first2, InputIt last2 );

// (4) Non const version only
constexpr basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr, size_type count2 );

// (4) Non const version only
constexpr basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr, size_type count2 );

// (5) Non const version only
constexpr basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr );

// (5) Non const version only
constexpr basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr );

// (6) Non const version only
constexpr basic_string& replace( size_type pos, size_type count,
                       size_type count2, CharT ch );

// (6) Non const version only
constexpr basic_string& replace( const_iterator first, const_iterator last,
                       size_type count2, CharT ch );

// (7) Non const version only
constexpr basic_string& replace( const_iterator first, const_iterator last,
                       std::initializer_list<CharT> ilist );

// (8) Non const version only
template < class StringViewLike >
constexpr basic_string& replace( size_type pos, size_type count,
                       const StringViewLike& t );

// (8) Non const version only
template < class StringViewLike >
constexpr basic_string& replace( const_iterator first, const_iterator last,
                       const StringViewLike& t );

// (9) Non const version only
template < class StringViewLike >
constexpr basic_string& replace( size_type pos, size_type count, const StringViewLike& t,
                       size_type pos2, size_type count2 = npos );

自 C++17 起

// (1) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const basic_string& str );

// (1) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const basic_string& str );

// (2) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const basic_string& str,
                       size_type pos2, size_type count2 = npos );

// (3) Non const version only
template< class InputIt >
basic_string& replace( const_iterator first, const_iterator last,
                       InputIt first2, InputIt last2 );

// (4) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr, size_type count2 );

// (4) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr, size_type count2 );

// (5) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr );

// (5) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr );

// (6) Non const version only
basic_string& replace( size_type pos, size_type count,
                       size_type count2, CharT ch );

// (6) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       size_type count2, CharT ch );

// (7) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       std::initializer_list<CharT> ilist );

// (8) Non const version only
template < class StringViewLike >
basic_string& replace( size_type pos, size_type count,
                       const StringViewLike& t );

// (8) Non const version only
template < class StringViewLike >
basic_string& replace( const_iterator first, const_iterator last,
                       const StringViewLike& t );

// (9) Non const version only
template < class StringViewLike >
basic_string& replace( size_type pos, size_type count, const StringViewLike& t,
                       size_type pos2, size_type count2 = npos );

自 C++14 起

// (1) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const basic_string& str );

// (1) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const basic_string& str );

// (2) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const basic_string& str,
                       size_type pos2, size_type count2 = npos );

// (3) Non const version only
template< class InputIt >
basic_string& replace( const_iterator first, const_iterator last,
                       InputIt first2, InputIt last2 );

// (4) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr, size_type count2 );

// (4) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr, size_type count2 );

// (5) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr );

// (5) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr );

// (6) Non const version only
basic_string& replace( size_type pos, size_type count,
                       size_type count2, CharT ch );

// (6) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       size_type count2, CharT ch );

// (7) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       std::initializer_list<CharT> ilist );

自 C++11 起

// (1) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const basic_string& str );

// (1) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const basic_string& str );

// (2) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const basic_string& str );

// (3) Non const version only
template< class InputIt >
basic_string& replace( const_iterator first, const_iterator last,
                       InputIt first2, InputIt last2 );


// (4) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr, size_type count2 );

// (4) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr, size_type count2 );

// (5) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr );

// (5) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr );

// (6) Non const version only
basic_string& replace( size_type pos, size_type count,
                       size_type count2, CharT ch );

// (6) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       size_type count2, CharT ch );

// (7) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       std::initializer_list<CharT> ilist );

直到 C++11

// (1) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const basic_string& str );

// (1) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const basic_string& str );

// (2) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const basic_string& str );


// (3) Non const version only
template< class InputIt >
basic_string& replace( const_iterator first, const_iterator last,
                       InputIt first2, InputIt last2 );

// (4) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr, size_type count2 );

// (4) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr, size_type count2 );

// (5) Non const version only
basic_string& replace( size_type pos, size_type count,
                       const CharT* cstr );

// (5) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       const CharT* cstr );

// (6) Non const version only
basic_string& replace( size_type pos, size_type count,
                       size_type count2, CharT ch );

// (6) Non const version only
basic_string& replace( const_iterator first, const_iterator last,
                       size_type count2, CharT ch );

用一个新字符串替换由 [ pos, pos + count ) 或 [ first, last ) 指示的字符串部分。

新字符串可以是以下之一：

• (1) 字符串 str。

• (2) str 的子字符串 [ pos2, pos2 + count2 )，除非 count2 == npos 或它会超出 str.size()，在这种情况下使用 [ pos2, str.size() )。

• (3) 范围 [ first2, last2 ) 中的字符。

  自 C++11 起

  重载决议

  当且仅当 InputIt 符合 LegacyInputIterator 的条件时，此重载才参与重载决议。

  直到 C++11

  如果 InputIt 是整数类型，则此重载与重载 (6) 具有相同的效果。

• (4) 范围 [ cstr, cstr + count2 ) 中的字符。

• (5) 范围 [ cstr, cstr + Traits::length(cstr) ) 中的字符。

• (6) count2 个字符 ch 的副本。

• (7) 初始化列表 ilist 中的字符。

• (8) 字符串视图 sv 中的字符，如同通过 std::basic_string_view<CharT, Traits> sv = t; 从 t 转换而来。

  重载决议

  当且仅当 std::is_convertible_v<const StringViewLike&, std::basic_string_view<CharT, Traits>> 为 true 且 std::is_convertible_v<const StringViewLike&, const CharT*> 为 false 时，这些重载才参与重载决议。

• (9) 字符串视图 sv 的子视图 [ pos2, pos2 + count2 )，如同通过 std::basic_string_view<CharT, Traits> sv = t; 从 t 转换而来，除非 count2 == npos 或它会超出 sv.size()，在这种情况下使用 [ pos2, sv.size() )。

  重载决议

  当且仅当 std::is_convertible_v<const StringViewLike&, std::basic_string_view<CharT, Traits>> 为 true 且 std::is_convertible_v<const StringViewLike&, const CharT*> 为 false 时，此重载才参与重载决议。

:::

参数

• pos - 要替换的子字符串的起始位置
• count - 要替换的子字符串的长度
• first, last - 要替换的字符范围
• str - 用于替换的字符串
• pos2 - 用于替换的子字符串的起始位置
• count2 - 用于替换的字符数
• cstr - 指向用于替换的字符字符串的指针
• ch - 用于替换的字符值
• first2, last2 - 用于替换的字符范围
• ilist - 带有用于替换的字符的std::initializer_list
• t - 带有用于替换的字符的对象（可转换为std::basic_string_view）

返回值

*this

复杂度

重要

本节需要改进。您可以通过编辑此文档页面来帮助我们。

异常

• 如果 pos > length() 或 pos2 > str.length()，则为std::out_of_range。
• 如果结果字符串将超过最大可能的字符串长度（max_size()），则为std::length_error。

在任何情况下，如果由于任何原因抛出异常，此函数无效（强异常保证）。 (自 C++11 起)

示例

Main.cpp

#include <cassert>
#include <iterator>
#include <string>
 
using namespace std::string_literals;
 
int main()
{
    std::string s = "xmplr";
 
    // replace(size_type index, size_type count, char ch)
    s.replace(0, 1, 'E');
    assert("Exmplr" == s);
 
    // replace(size_type index, const char* s)
    s.replace(2, "e");
    assert("Exemplr" == s);
 
    // replace(size_type index, string const& str)
    s.replace(6, "a"s);
    assert("Exemplar" == s);
 
    // replace(size_type index, string const& str,
    //        size_type index_str, size_type count)
    s.replace(8, " is an example string."s, 0, 14);
    assert("Exemplar is an example" == s);
 
    // replace(const_iterator pos, char ch)
    s.replace(s.cbegin() + s.find_first_of('n') + 1, ':');
    assert("Exemplar is an: example" == s);
 
    // replace(const_iterator pos, size_type count, char ch)
    s.replace(s.cbegin() + s.find_first_of(':') + 1, 2, '=');
    assert("Exemplar is an:== example" == s);
 
    // replace(const_iterator pos, InputIt first, InputIt last)
    {
        std::string seq = " string";
        s.replace(s.begin() + s.find_last_of('e') + 1,
            std::begin(seq), std::end(seq));
        assert("Exemplar is an:== example string" == s);
    }
 
    // replace(const_iterator pos, std::initializer_list<char>)
    s.replace(s.cbegin() + s.find_first_of('g') + 1, { '.' });
    assert("Exemplar is an:== example string." == s);
}