How to check if there is a space in an input line in C++

I am trying to check if there is a space in an input line.

I have indexed the input but I got an error: "Expected ';' expected ')' "

string mike20;
int count = 0;

while (getline(cin, mike20))


for (mike20[0]); (isspace(mike20[0]); ++mike20[0])


return 0;