dcsimg
Login | Register   
RSS Feed
Download our iPhone app
TODAY'S HEADLINES  |   ARTICLE ARCHIVE  |   FORUMS  |   TIP BANK
Browse DevX
Sign up for e-mail newsletters from DevX

By submitting your information, you agree that devx.com may send you DevX offers via email, phone and text message, as well as email offers about other products and services that DevX believes may be of interest to you. DevX will process your information in accordance with the Quinstreet Privacy Policy.


Tip of the Day
Language: C++
Expertise: Beginner
Sep 18, 2000

WEBINAR:

On-Demand

Application Security Testing: An Integral Part of DevOps


Checking If a Function Pointer is Valid

Question:
I am collecting a number of function pointers in C++ and before I call them I want to check to see if they have been set. I really want to avoid calling them if they aren't valid. I have tried the following "if func != Null { ... " but I get an error.

Answer:
First of all, there's no 'Null' in C++. The constant NULL is all uppercase. However, it's not a keyword so you have to #include a header file to make its definition visible to the compiler. The best way check for nullness is to compare the pointer (any type of pointer, including a pointer to member) to the literal zero:

if (pmf!=0)
DevX Pro
 
Comment and Contribute

 

 

 

 

 


(Maximum characters: 1200). You have 1200 characters left.

 

 

Sitemap
Thanks for your registration, follow us on our social networks to keep up-to-date