exercises 3.6

 1 #include <iostream>
 2 #include <string>
 3 using namespace std;
 4 
 5 
 6 int main()
 7 {
 8     string str("some thing");
 9     for(auto &c:str)
10         if(!isspace(c))
11             c=‘X‘;
12     
13     cout<<str<<endl;
14     return 0;
15 }

 1 #include <iostream>
 2 #include <string>
 3 using namespace std;
 4 
 5 
 6 int main()
 7 {
 8     string str("some thing");
 9     for(decltype(str.size()) i = 0 ; i<str.size() ; ++i)
10         if(!isspace(str[i]))str[i]=‘X‘;
11     
12     cout<<str<<endl;
13     return 0;
14 }