C++ 字符串 5-- 18.16~17.string型字符串的替换

#include <iostream>
#include <string>
using namespace std;
/*---------------------------------
     18-16 18.16~17.string型字符串的替换
---------------------------------*/
int main()
{
cout<<"------strncpy------------:"<<endl;
char ch1[50]="1234567890"; 
char ch2[]="abcd";
cout<<ch1<<endl<<ch2<<endl;
strncpy(ch1,ch2,3);       //连接字符串
cout<<ch1<<endl<<ch2<<endl;


cout<<"-------replace-----------:"<<endl;
string str1="1234567890"; 
string str2="abcdefg";
cout<<str1<<endl<<str2<<endl;
//用str2中脚标4开始的两个字符替换str1中脚标0开始的最多1个字符，多的字符插入即可
str1.replace(0,1,str2,4,2); 
cout<<str1<<endl<<str2<<endl;


return 0;

}

运行结果：

------strncpy------------:
1234567890
abcd
abc4567890
abcd
-------replace-----------:
1234567890
abcdefg
ef234567890
abcdefg
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