关于replace的问题

[hexuan1982]

请问C++中有replace这个系统函数吗？请教下面代码中的replace里每个参数的含义。

while((pos = str.find("{num:1}")) != string::npos)
{
str.replace(pos, 7, szNumber, 8, 1);
}

[p0303230]

Examines   each   element   in   a   range   and   replaces   it   if   it   matches   a   specified   value.   
  template<class   ForwardIterator,   class   Type>   
        void   replace(   
              ForwardIterator   _First,     
              ForwardIterator   _Last,   
              const   Type&   _OldVal,     
              const   Type&   _NewVal   
        );   
  _First   
  A   forward   iterator   pointing   to   the   position   of   the   first   element   in   the   range   from   which   elements   are   being   replaced.   
    
  _Last   
  A   forward   iterator   pointing   to   the   position   one   past   the   final   element   in   the   range   from   which   elements   are   being   replaced.   
    
  _OldVal   
  The   old   value   of   the   elements   being   replaced.   
    
  _NewVal   
  The   new   value   being   assigned   to   the   elements   with   the   old   value.   

[p0303230]

http://topic.csdn.net/t/20060721/14/4895939.html

[Supper_Jerry]

basic_string& replace(size_type p0, size_type n0,
const basic_string& str, size_type pos, size_type n);
Each member function replaces up to n0 elements of the controlled sequence beginning with position p0, or the elements of the controlled sequence beginning with the one pointed to by first, up to but not including last. The replacement is the operand sequence specified by the remaining operands. The function then returns *this.

[Supper_Jerry]

str.replace(pos, 7, szNumber, 8, 1);
pos表示需要替换的起始位置，也就是{num:1}的位置
7表示替换7个元素，{num:1}刚好7个
szNumber表示用szNumber中的字符串替换
8表示szNumber第8为开始
1表示用1个元素来替换

[Supper_Jerry]

楼主，结贴吧。

[Chappell]

#include   <string>   
#include   <iostream>   

using   namespace   std;   

string&   replace_all(string&   str,const   string&   old_value,const   string&   new_value)   
{   
	while(true)  
	{   
		string::size_type   pos(0);   
		if(   (pos=str.find(old_value))!=string::npos   )   
			str.replace(pos,old_value.length(),new_value);   
		else   break;   
	}   
	return   str;   
}   

string&   replace_all_distinct(string&   str,const   string&   old_value,const   string&   new_value)   
{   
	for(string::size_type   pos(0);   pos!=string::npos;   pos+=new_value.length())   {   
		if(   (pos=str.find(old_value,pos))!=string::npos   )   
			str.replace(pos,old_value.length(),new_value);   
		else   break;   
	}   
	return   str;   
}   

int   main()   
{   
	cout   <<   replace_all(string("12212"),"12","21")   <<   endl;   
	cout   <<   replace_all_distinct(string("12212"),"12","21")   <<   endl;   
}   

  //output:   
  //22211   
  //21221

[Chappell]

(*^__^*) 嘻嘻……