//字串替換
//eg: str1=”123%s456%s” str2={‘a’,’b’,’c’,’d’}(將str1中的%s替換成str2中的字元)替換結果返回為：123a456bcd

程式碼塊

#pragma once
#include<iostream>
using namespace std;
#include<assert.h>
#include<string>

void  ReplaceCharacterString(string &str1,int len1, const string str2, int len2)
{
    assert(str1.c_str());
    int
 
 j = 0;
    int i = 0;
    for (i = 0; i < len1; ++i)
    {
        if (str1[i] == '%')
        {
            if (str1[i + 1] == 's')
            {
                str1.erase(i, 1);//刪除str1第i個1個字元
                --len1;
                str1[i] = str2[j++];
            }
        }
    }
    if (j < len2)
    {
        str1.append(str2, j, len2-j);//將str2的剩餘字串追加到str1後
 

    }
}
void RepCharStrTest()
{
    string str1 = "123%s456%s";//10
    //int len1 = strlen(str1.c_str());//法一
    int len1 = str1.size();//法二
    cout << "原str1: " << str1 <<"長度為："<<len1<< endl;

    string str2 = { 'a', 'b', 'c', 'd' };//4
    int len2 = strlen(str2.c_str());
    cout
 
 << "原str2: " << str2 << "長度為：" << len2 << endl;

    ReplaceCharacterString(str1, len1, str2, len2);

    cout << "替換後的str1: " << str1 << "長度為：" << strlen(str1.c_str()) << endl;

}

結果顯示