Assertion in Java

Assertion facility is added in J2SE 1.4. In order to support this facility J2SE 1.4 added the keyword assert to the language, and AssertionError class. An assertion checks a boolean-typed expression that must be true during program runtime execution. The assertion facility can be enabled or disable at runtime.

Declaring Assertion

Assertion statements have two forms as given below

assert expression;

assert expression1 : expression2;

The first form is simple form of assertion, while second form takes another expression. In both of the form boolean expression represents condition that must be evaluate to true runtime.

If the condition evaluates to false and assertions are enabled, AssertionError will be thrown at runtime.

Some examples that use simple assertion form are as follows.

assert value > 5 ;

assert accontBalance > 0;

assert isStatusEnabled();

The expression that has to be asserted runtime must be boolean value. In third example isStatusEnabled() must return boolean value. If condition evaluates to true, execution continues normally, otherwise the AssertionError is thrown.

Following program uses simple form of assertion

//AssertionDemo.java

Class AssertionDemo{

Public static void main(String args[]){

System.out.println( withdrawMoney(1000,500) );

System.out.println( withdrawMoney(1000,2000) );

}

public double withdrawMoney(double balance , double amount){

assert balance >= amount;

return balance ? amount;

}

}

In above given example, main method calls withdrawMoney method with balance and amount as arguments. The withdrawMoney method has a assert statement that checks whether the balance is grater than or equal to amount to be withdrawn. In first call the method will execute without any exception, but in second call it AssertionError is thrown if the assertion is enabled at runtime.

Enable/Disable Assertions

By default assertion are not enabled, but compiler complains if assert is used as an identifier or label. The following command will compile AssertionDemo with assertion enabled.

javac ?source 1.4 AssertionDemo.java

The resulting AssertionDemo class file will contain assertion code.

By default assertion are disabled in Java runtime environment. The argument ?eanbleassertion or ?ea will enables assertion, while ?disableassertion or ?da will disable assertions at runtime.

The following command will run AssertionDemo with assertion enabled.

Java ?ea AssertionDemo

or

Java ?enableassertion AssertionDemo

Second form of Assertion

The second form of assertion takes another expression as an argument.

The syntax is,

assert expression1 : expression2;

where expression1 is the condition and must evaluate to true at runtime.

This statement is equivalent to

assert expression1 : throw new AssertionError(expression2);

Note: AssertionError is unchecked exception, because it is inherited from Error class.

Here, expression2 must evaluate to some value.

By default AssertionError doesn't provide useful message so this form can be helpful to display some informative message to the user.

Rahim Vindhani
Application Develper [Application Development & Webservices]
IBM Global Services, pune, India
email: rahim.vindhani@gmail.com
web: http://www.rahim.co.nr

green cleaning service Glencoe ..
In The News:

Fake buyers demand specific vehicle reports from unknown sites to steal credit card information from car sellers, but warning signs can help identify these scams before paying.
Android users can now manage apps across multiple devices more easily with Google Play Store's updated remote uninstall button in the latest update.
NASA's Perseverance rover discovers shiny metallic rock on Mars that could be a meteorite from an ancient asteroid, containing high levels of iron and nickel.
Holiday scams spike during Black Friday and Cyber Monday as criminals exploit your leaked personal data. Learn how to protect yourself from fake stores and phishing.
Commerce Department proposes TP-Link router ban over Chinese security risks. Learn how this potential prohibition could affect your home network and devices.
Hyundai AutoEver America suffered a data breach affecting 2,000 current and former employees, exposing names, Social Security numbers and driver's license information.
Washington court rules automated license plate reader images are public records, even when stored by vendors like Flock Safety, setting precedent for transparency.
Fake airline texts claiming flight cancellations are targeting travelers with convincing scams. Learn how cybercriminals steal personal data and credit card info.
Discover how iOS 26's new Adaptive Power feature automatically extends iPhone battery life by learning your usage patterns and adjusting performance intelligently.
New TikTok malware campaign tricks users into running PowerShell commands that download Aura Stealer, which steals credentials and authentication tokens.
Gaia Family offers fixed upfront pricing for IVF cycles with unlimited embryo transfers and financial protection, partnering with over 100 U.S. fertility clinics.
The Jetsons Act aims to position Pennsylvania as a leader in advanced air mobility by establishing regulations for hybrid ground-air vehicles.
Fake Geek Squad invoice emails are targeting users with convincing charges and urgent phone numbers to steal personal information and money.
Fox News Digital's artificial intelligence newsletter digs into a robot in Russia that faceplanted, George Clooney's alarm and OpenAI's rivalry with the New York Times.
Major data breach at Conduent exposes personal information of 10+ million people. Government contractor hit by cyberattack affecting Medicaid, child support systems.
Texas startup Janta Power raises $5.5M for innovative vertical solar towers that generate 50% more energy than traditional panels while using just one-third the land.
NASA's twin ESCAPADE spacecraft launched aboard Blue Origin's New Glenn rocket Thursday afternoon from Cape Canaveral, beginning their journey to Mars with arrival expected in 2027.
Learn how to set email reminders on iPhone and Android so you never forget to reply again. Simple built-in features help you stay organized and on top of messages.
Discover how Apple's passkeys revolutionize Mac security by replacing vulnerable passwords with biometric authentication and encryption for ultimate protection.
New survey reveals 78% of parents fear AI scams targeting their kids, yet nearly half haven't discussed these threats. Learn why this dangerous gap exists.
Chrome now autofills passport and driver's license info automatically. Google's latest browser update adds official document support with encryption and user control.
Scammers impersonate Department of Veterans Affairs employees claiming veterans owe money, but real VA communications only direct to VA.gov or official channels.
The AltoVolo Sigma hybrid-electric aircraft flies 500 miles at 220 mph while operating 80% quieter than helicopters, featuring safety systems and compact design.
Google search scam alert: fake customer service numbers can give scammers remote control of your phone. Learn how to spot these traps and protect yourself.
Electric vehicles overtake gas cars in total CO2 savings after just two years of driving, with emissions benefits growing over time as power grids get cleaner.

Screenplay and Script Writing Software

When it comes to screenplay software each screenwriter needs to... Read More

Corporate ERP: Microsoft Great Plains For The Plant In Brazil ? Overview For CIO

Microsoft Business Solutions Great Plains as new ERP for multinational... Read More

Microsoft CRM Integration with IBM Lotus Notes Domino ? Machinery Dealership Example

IBM Lotus Notes with Domino email server is traditional document... Read More

Microsoft CRM Customization

Microsoft CRM customization techniques are very diversified and based on... Read More

Microsoft CRM or Siebel

Siebel is traditional CRM market leader, however and mostly due... Read More

Lotus Domino: Reports and Connectors ? Crystal Reports, XML, ODBC/JDBC, OLE

Lotus Notes Domino is very efficient in electronic document workflow... Read More

Benefits of Integrating Online Chat Software with CRM

Customer Relationship Management (CRM) is a strategy and processes used... Read More

Great Plains Bill of Materials Setup & Customization for Process Manufacturing ? Overview

Microsoft Great Plains has full-featured Manufacturing suite of modules: Capacity... Read More

XML Parser and Their Types

XML parser is a software module to read documents and... Read More

Rapid Application Development - Is it Really a Need of Today?

Rapid Application Development (RAD) is a software development methodology. In... Read More

Microsoft Great Plains Implementation ? Overview for IT Director/Controller

What is installation in the language of technology? Installation... Read More

Manufacturing Solutions for Microsoft Great Plains ? Overview for Consultant

Microsoft Business Solutions Great Plains has full-featured manufacturing set of... Read More

Microsoft Great Plains - Typical Problems And Fixes ? Overview For IT Administrators

How to delete the user? This is the first problem... Read More

String in Java

Handling character strings in Java is supported through two final... Read More

.Net Charts and Graphs Interact with Businesses and Customers

Bar charts, bar graphs, and any other chart or graph... Read More

Great Plains Dexterity Development: FAQ

Microsoft Business Solutions Great Plains is Dexterity-written application and currently... Read More

Great Plains DOS Support ? Notes for Consultant

Great Plains Accounting, accounting package for mid-size and small companies... Read More

Microsoft Office Selecting Secrets

Stop the Runaway MouseWhat's the "runaway mouse?" You've seen it...you... Read More

Introduction To ISDN, Part II

In the previous ISDN article, we looked at how and... Read More

SyncUp ? A File/Folder Synchronizer For Windows

SyncUp, a file synchronizer is designed to assist the home... Read More

Mapping Software: Putting Data Visualization on the Map

Mapping Software Improves Data VisualizationFrom the outset, it is important... Read More

Hear It in Digits

Music downloads are off the charts! We're listening to digital... Read More

How to Evaluate Staffing Software

If you are in the market for new staffing software,... Read More

An Easy Way to Deal with Email Viruses and Worms

If you feel intimidated when someone tries to teach you... Read More

Microsoft Great Plains Multicurrency ? Overview For Implementation Consultant

When you first think about multicurrency ? you probably have... Read More

house cleaning company Bannockburn ..