c++ find() returning a different value when stored as a variable

I was helping someone with some homework when I came upon something strange. I don't use C++, but I figured the function find() would work like any other language. However, in the first example below, an email with the name ericsomthing@gmail.com does not evaluate true when looking for a space using find(' ').

if (classRosterArray[i]->GetEmailAddress().find(' ') >= 0) // evaluated true even though i dont know why

In the second example, find(' ') works but only when stored in a local variable.

int test = classRosterArray[i]->GetEmailAddress().find(' ');
if (test >= 0) // evaluates false as expected

More verbose example of the code is shown below

Strange broken code:

void Tester::printInvalidEmails() {
    NUM_STUDENTS = LAST_INDEX + 1;
    for (int i = 0; i < NUM_STUDENTS; ++i) {
        int test = classRosterArray[i]->GetEmailAddress().find(' ');
        int test1 = classRosterArray[i]->GetEmailAddress().find('@');
        int test2 = classRosterArray[i]->GetEmailAddress().find('.');
        if (classRosterArray[i]->GetEmailAddress().find(' ') >= 0) {
            cout << classRosterArray[i]->GetEmailAddress() << endl;
        }
        if (classRosterArray[i]->GetEmailAddress().find('@') == -1) {
            cout << classRosterArray[i]->GetEmailAddress() << endl;
        }
        if (classRosterArray[i]->GetEmailAddress().find('.') == -1 ) {
            cout << classRosterArray[i]->GetEmailAddress() << endl;
        }
    }
}

But this code works:

void Tester::printInvalidEmails() {
    NUM_STUDENTS = LAST_INDEX + 1;
    for (int i = 0; i < NUM_STUDENTS; ++i) {
        int test = classRosterArray[i]->GetEmailAddress().find(' ');
        int test1 = classRosterArray[i]->GetEmailAddress().find('@');
        int test2 = classRosterArray[i]->GetEmailAddress().find('.');
        if (test >= 0) {
            cout << classRosterArray[i]->GetEmailAddress() << endl;
        }
        if (test1 == -1) {
            cout << classRosterArray[i]->GetEmailAddress() << endl;
        }
        if (test2  == -1 ) {
            cout << classRosterArray[i]->GetEmailAddress() << endl;
        }
    }
}

Why does storing the value of find as a local variable 'test' fix the problem?