Code Smell 73 — Exceptions for Expected Cases

Exceptions are handy Gotos and flags. Let’s abuse them.

Photo by Greg Rosenke on Unsplash

TL;DR: Do not use exceptions for flow control.

Problems

• Readability
• Principle of least astonishment Violation.

Solutions

1. Use Exceptions just for unexpected situations.

2. Exceptions handle contract violations. Read the contract.

Sample Code

Wrong

Right

Detection

This is a semantic smell. Unless we use machine learning linters it will be very difficult to find the mistakes.

Tags

• Readability

Conclusion

Exceptions are handy, and we should definitively use them instead of returning codes.

The boundary between correct usage and wrong usage is blur like so many design principles.

Relations

Code Smell 72 — Return Codes

Code Smell 26 — Exceptions Polluting

More info

https://wiki.c2.com/?DontUseExceptionsForFlowControl

Why You Should Avoid Using Exceptions as the Control Flow in Java - DZone Java

Are exceptions as control flow considered a serious antipattern? If so, Why?

Why not use exceptions as regular flow of control?

When debugging, novices insert corrective code; experts remove defective code.

Richard Pattis

Software Engineering Great Quotes

This article is part of the CodeSmell Series.

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