How can you avoid unnecessary type conversions and casts?

1 Why are type conversions and casts expensive?

Type conversions and casts can have a negative impact on your code performance for several reasons. First, they can consume extra CPU cycles and memory, especially when they involve complex objects or arrays. Second, they can introduce runtime errors or unexpected behaviors, such as loss of precision, overflow, or null pointer exceptions. Third, they can reduce the benefits of polymorphism and inheritance, which are key features of object oriented design. For example, if you cast a subclass object to its superclass type, you lose access to the subclass-specific methods and attributes.

2 How to avoid implicit type conversions?

Implicit type conversions can be convenient, but they can also cause potential bugs or performance bottleneecs. To avoid implicit type conversions, you should use consistent and appropriate data types for your variables, parameters, and return values; for instance, avoid mixing integers and floating-point numbers, or strings and numbers. Additionally, it is important to use strict comparison operators such as === in JavaScript or == in Java instead of loose ones like == in JavaScript or equals() in Java. This will prevent implicit type conversions from resulting in unexpected results. Lastly, using explicit type annotations or declarations, if your programming language supports them, can help you catch type errors at compile time. For example, in TypeScript or C# you can specify the type of your variables, parameters, and return values.

3 How to avoid explicit type conversions and casts?

Explicit type conversions and casts are those that you perform intentionally in your code, using operators or methods. Although they can be necessary in certain cases, you should avoid them whenever possible, as they can cause performance and readability issues. To avoid explicit type conversions and casts, you can consider alternatives such as polymorphism and inheritance to design classes and interfaces, generics or templates to create generic classes and methods, or design patterns such as the adapter pattern or the strategy pattern to create wrapper classes or objects. For example, in Java or C#, you can use a generic List<T> class to store and manipulate objects of any type T without casting them to a specific type. Alternatively, an adapter class can be used to implement a common interface that can work with different types of data sources.

4 How to test and measure the impact of type conversions and casts?

Even if you follow the previous tips, you may still need to use some type conversions and casts in your code, depending on your requirements and constraints. In that case, you should test and measure the impact of type conversions and casts on your code performance, and optimize them if necessary. To do this, you can use profiling tools such as Visual Studio Profiler or PyCharm Profiler to identify hotspots and bottlenecks in your code. Benchmarking tools like JMH or Google Benchmark can be used to compare the performance of different implementations or solutions that use different types or conversions. Unit testing and integration testing tools such as JUnit or PyTest can verify the correctness and functionality of your code, while code analysis tools like SonarQube or Pylint can check the quality and readability of your code for any code smells or anti-patterns related to type conversions or casts. Refactoring tools like Eclipse or PyCharm can be used to improve and simplify your code, while code review tools like GitHub or Gerrit can provide feedback from peers or mentors. Type conversions and casts are inevitable in some situations, but they can also be avoided or minimized in many cases by applying object-oriented design principles and patterns. This will help you write code that is more performant, readable, and maintainable while effectively using types efficiently.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?