Determining Stack Content Type

Question:
Only Objects can be popped from, or push onto, a stack. That means Ihave to wrap a primitive data type, such as int, with something akin toInteger before pushing it onto a stack. How can I identify the typeof an object popped from a stack?

Answer:
Ideally, when you store objects in any type of container, you alreadyknow what their type is, or at least what class they derive from orwhat interface they implement. One of the most useful features ofobject oriented programming languages is polymorphism. Polymorphismallows you to define different behaviors for objects, yet access themin the same way.

For example, the AWT Component paint() method willdraw a component. Yet a List looks different from a Button. If youare writing one of those rare programs where you need to storemultiple objects of undetermined types in a container, you can resortto using the instanceof operator to identify the type of object youare dealing with. For example:

if (obj instanceof Integer) ...

This will tell you if an object is an Integer. The instanceof operator canhave a relatively high overhead if used excessively, so you should tryto structure your programs so as not to require its use.

Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

The Latest

iOS app development

The Future of iOS App Development: Trends to Watch

When it launched in 2008, the Apple App Store only had 500 apps available. By the first quarter of 2022, the store had about 2.18 million iOS-exclusive apps. Average monthly app releases for the platform reached 34,000 in the first half of 2022, indicating rapid growth in iOS app development.

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