When your code loses its way TL;DR: Missing return statements cause unexpected behavior. Problems 😔 Silent failures
Unreliable results
Hard debugging
Inconsistent and misleading behavior
Broken logic Solutions 😃 Always return values
Use clear flow
Validate conditions
Test all return paths
Use early returns
Remove IFs Refactorings ⚙️ https://hackernoon.com/refactoring-014-how-to-remove-if?embedable=true Context 💬 When you forget to return a value, your function keeps executing and your app might show incomplete or wrong information. Sample Code 📖 Wrong ❌ fun totalDistance(activity: Activity): Double {
    if (activity.type == "Running") {
        activity.calculateDistance() 
        // Missing return here
    } else {
        return 0.0
    }
    // Other options are omitted for simplicity
    // Some languages raise a runtime error 
    // If the function does not return a value
    // of the correct type (in this case a Double)
} Right 👉 fun totalDistance(activity: Activity): Double {
    if (activity.type == "Running") {
        return activity.calculateDistance() 
        // Now it returns the value
    } else {
        return 0.0
    }
} Detection 🔍 [x]Automatic You can detect this smell when your function lacks a return statement in certain branches. Most static analyzers and linters often catch this. Tags 🏷️ IFs Level 🔋 [x]Beginner Why the Bijection Is Important 🗺️ it's important to maintain a clear and predictable relationship between your code and the Real World. If a function is intended to calculate and return a value, it should always do so. Failing to return a value breaks the MAPPER, leading to inaccurate behavior and unreliable results. AI Generation 🤖 AI tools usually don't generate this smell. AI Detection 🥃 Most AI-powered linters quickly catch missing returns with static analysis or by examining your code's Abstract Syntax Tree. Try Them! 🛠 Remember: AI Assistants make lots of mistakes Without Proper Instructions

With Specific Instructions



ChatGPT

ChatGPT



Claude

Claude



Perplexity

Perplexity



Copilot

Copilot



Gemini

Gemini



DeepSeek

DeepSeek



Meta AI

Meta AI Conclusion 🏁 A missing return statement breaks your code’s flow and produces unreliable results. Always ensure every branch in your function returns something meaningful. Relations 👩‍❤️‍💋‍👨 https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xv https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxi https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxiii https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxiv https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxxviii https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-viii-8mn3352 https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxxii Disclaimer 📘 Code Smells are my opinion. Credits 🙏 Photo by Tim Johnson on Unsplash A bug is never just a mistake. It represents something bigger. Sergey Zefirov https://hackernoon.com/400-thought-provoking-software-engineering-quotes?embedable=true This article is part of the CodeSmell Series. https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-i-xqz3evd?embedable=true When your code loses its way When your code loses its way TL;DR: Missing return statements cause unexpected behavior. TL;DR: Missing return statements cause unexpected behavior. Problems 😔 Silent failures Unreliable results Hard debugging Inconsistent and misleading behavior Broken logic Silent failures Unreliable results Hard debugging Inconsistent and misleading behavior Broken logic Solutions 😃 Always return values Use clear flow Validate conditions Test all return paths Use early returns Remove IFs Always return values Use clear flow Validate conditions Test all return paths Use early returns early returns Remove IFs IFs Refactorings ⚙️ https://hackernoon.com/refactoring-014-how-to-remove-if?embedable=true https://hackernoon.com/refactoring-014-how-to-remove-if?embedable=true Context 💬 When you forget to return a value, your function keeps executing and your app might show incomplete or wrong information. Sample Code 📖 Wrong ❌ fun totalDistance(activity: Activity): Double {
    if (activity.type == "Running") {
        activity.calculateDistance() 
        // Missing return here
    } else {
        return 0.0
    }
    // Other options are omitted for simplicity
    // Some languages raise a runtime error 
    // If the function does not return a value
    // of the correct type (in this case a Double)
} fun totalDistance(activity: Activity): Double {
    if (activity.type == "Running") {
        activity.calculateDistance() 
        // Missing return here
    } else {
        return 0.0
    }
    // Other options are omitted for simplicity
    // Some languages raise a runtime error 
    // If the function does not return a value
    // of the correct type (in this case a Double)
} Right 👉 fun totalDistance(activity: Activity): Double {
    if (activity.type == "Running") {
        return activity.calculateDistance() 
        // Now it returns the value
    } else {
        return 0.0
    }
} fun totalDistance(activity: Activity): Double {
    if (activity.type == "Running") {
        return activity.calculateDistance() 
        // Now it returns the value
    } else {
        return 0.0
    }
} Detection 🔍 [x]Automatic [x] Automatic [x] You can detect this smell when your function lacks a return statement in certain branches. Most static analyzers and linters often catch this. Tags 🏷️ IFs IFs Level 🔋 [x]Beginner [x] Beginner [x] Why the Bijection Is Important 🗺️ it's important to maintain a clear and predictable relationship between your code and the Real World . Real World If a function is intended to calculate and return a value, it should always do so. Failing to return a value breaks the MAPPER , leading to inaccurate behavior and unreliable results. MAPPER AI Generation 🤖 AI tools usually don't generate this smell. AI Detection 🥃 Most AI-powered linters quickly catch missing returns with static analysis or by examining your code's Abstract Syntax Tree . Abstract Syntax Tree Try Them! 🛠 Remember: AI Assistants make lots of mistakes Remember: AI Assistants make lots of mistakes Without Proper Instructions

With Specific Instructions



ChatGPT

ChatGPT



Claude

Claude



Perplexity

Perplexity



Copilot

Copilot



Gemini

Gemini



DeepSeek

DeepSeek



Meta AI

Meta AI Without Proper Instructions

With Specific Instructions ChatGPT

ChatGPT Claude

Claude Perplexity

Perplexity Copilot

Copilot Gemini

Gemini DeepSeek

DeepSeek Meta AI

Meta AI Without Proper Instructions With Specific Instructions Without Proper Instructions Without Proper Instructions With Specific Instructions With Specific Instructions ChatGPT ChatGPT ChatGPT ChatGPT ChatGPT ChatGPT ChatGPT ChatGPT Claude Claude Claude Claude Claude Claude Claude Claude Perplexity Perplexity Perplexity Perplexity Perplexity Perplexity Perplexity Perplexity Copilot Copilot Copilot Copilot Copilot Copilot Copilot Copilot Gemini Gemini Gemini Gemini Gemini Gemini Gemini Gemini DeepSeek DeepSeek DeepSeek DeepSeek DeepSeek DeepSeek DeepSeek DeepSeek Meta AI Meta AI Meta AI Meta AI Meta AI Meta AI Meta AI Meta AI Conclusion 🏁 A missing return statement breaks your code’s flow and produces unreliable results. Always ensure every branch in your function returns something meaningful. Relations 👩‍❤️‍💋‍👨 https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xv https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xv https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxi https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxi https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxiii https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxiii https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxiv https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxiv https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxxviii https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxxviii https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-viii-8mn3352 https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-viii-8mn3352 https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxxii https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-xxxii Disclaimer 📘 Code Smells are my opinion . opinion Credits 🙏 Photo by Tim Johnson on Unsplash Tim Johnson Unsplash A bug is never just a mistake. It represents something bigger. A bug is never just a mistake. It represents something bigger. Sergey Zefirov Sergey Zefirov https://hackernoon.com/400-thought-provoking-software-engineering-quotes?embedable=true https://hackernoon.com/400-thought-provoking-software-engineering-quotes?embedable=true This article is part of the CodeSmell Series. https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-i-xqz3evd?embedable=true https://hackernoon.com/how-to-find-the-stinky-parts-of-your-code-part-i-xqz3evd?embedable=true

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Code Smell 292 - Missing Return

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