A static class member

A class member declared static is a single instance of that member shared by all instances of this class (that’s why it is sometimes termed a class variable, as opposed to object variable). This feature has many uses: for instance, in order to create a file lock, one can use a static bool class member. An object trying to access this file has to check first whether the static (i.e., shared) flag is false. If it is, the object turns the flag on and processes the file safely, since other objects will now find that the flag is now on, and hence — they cannot access the file. When the object processing the file is done, it has to turn off the flag, enabling another object to access it. How is a static member created?

 class fileProc {	FILE *p;	static bool isLocked; //only a declaration; see definition below...	public:	bool isLocked () const {return isLocked; }};//somewhere outside the class definition:bool fileProc::isLocked; //definition; initialized to 'false' by default. Note: no 'static' here
Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

The Latest

microsoft careers

Top Careers at Microsoft

Microsoft has gained its position as one of the top companies in the world, and Microsoft careers are flourishing. This multinational company is efficiently developing popular software and computers with other consumer electronics. It is a dream come true for so many people to acquire a high paid, high-prestige job

your company's audio

4 Areas of Your Company Where Your Audio Really Matters

Your company probably relies on audio more than you realize. Whether you’re creating a spoken text message to a colleague or giving a speech, you want your audio to shine. Otherwise, you could cause avoidable friction points and potentially hurt your brand reputation. For example, let’s say you create a

chrome os developer mode

How to Turn on Chrome OS Developer Mode

Google’s Chrome OS is a popular operating system that is widely used on Chromebooks and other devices. While it is designed to be simple and user-friendly, there are times when users may want to access additional features and functionality. One way to do this is by turning on Chrome OS