Exercise 5.04

Explain each of the following examples, and correct any problems you detect.

(a) while (string::iterator iter != s.end()) { /* ... */ }
(b)

while (bool status = find(word)) { /* ... */ }
if (!status) { /* ... */ }

Solution

(a) The loop attempts to traverse the string s, but fails to initialize the iterator iter:

for (string::iterator iter = s.begin(); s != s.end(); ++iter) { /* ... */ }

(b) The if statement after the loop attempts to access status which is out of scope. The loop itself terminates when find(word) returns false.

bool status
while (status = find(word)) { /* ... */ }
if (!status) { /* ... */ }