Is this method to a String from a function going to cause memory corruption?

Question

I'd like to define a function such that I return a string and a boolean indicating whether the result is valid. Like this:

bool getStringOrTimeout(String *s) {
 ...
 if (timed_out) {
 return false;
 } else {
 *s = String(<some value>);
 return true;
 }
}

Is this going to cause a memory problem because the string is allocated on the stack and deallocated when it leaves scope, or is this okay?

• Nick Gammon: You don't need to use the String constructor there. You could just as easily have said: *s = "foo";

Answer 1

You are better off passing the string by reference, like this:

bool getStringOrTimeout(String & s)
{
 if (timed_out)
 return false;
 s = "foo";
 return true;
}

That means the caller's string will be modified. And you no longer need to pass down a pointer to a string.