C++ Primer（第五版）练习3.40

/*************************************************************************    > File Name: 3_40.cpp    > Author:     > Mail:     > Created Time: Wed 12 Apr 2017 09:53:17 PM CST ************************************************************************/#include<iostream>#include<cstring>using namespace std;int main(){    char s1[] = "hello";    char s2[] = "world";    char s3[20];    strcat(s1,s2);    strcpy(s3,s1);    cout<<s3<<endl;    return 0;}