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Arjun M S
Arjun M S

Posted on • Updated on • Originally published at dev.to

Static Typing VS Dynamic Typing: The Difference Explained

You’ve probably heard the terms “static typing” and “dynamic typing” thrown around in discussions of programming languages. But what do they mean, and why is it important to know?

To understand the difference between static and dynamic typing, let’s first talk about type checking. Type checking is a process used by compilers or interpreters to ensure that a program is written with correct syntax for each language. Static type checking will identify any errors when you’re writing code using a compiler, whereas dynamic type checking will identify any errors at runtime.

What is Static Typing?

Static typing is a convention used in many programming languages that defines the type of variable in the code. The type of a variable is determined at compile time(the period when the programming code is converted to the machine code).

Static typing can be beneficial for developers because it allows them to more easily understand the code they are writing and it can help them to prevent errors. Examples of statically typed programming languages include C, Java, C++,Scala, etc…

In simple words, Static typing means you tell the computer what type of data is in the program before the program starts.

Example in Java:

String x = “Hello world!”; // x is a string
int y = 15;  // y is an integer
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Advantages of Static Typing

Type safety can help prevent unintended type conversions (for example, between numeric types), which can produce incorrect results or cause runtime errors.
Static typing makes it easier for a new developer to understand and modify existing code, as the expected types of each variable can easily be determined through analysis of the source code itself.
It can help detect bugs earlier in the development cycle. The compiler or interpreter checks for type errors before running your code. This means you can find errors at compile time instead of being surprised at runtime when your code crashes.

What is Dynamic Typing?

Dynamic typing, a technique used in many programming languages and tools, is a method of determining the type of data being stored at runtime (i.e., when code is running). In contrast to static typing, where all variables are typed ahead of time and remain constant throughout a program’s execution, dynamic typing allows the data type of a variable to change during execution. This can be useful because it allows programmers to store different types of data in the same variable; however, it can also lead to unexpected errors in code.

In simple words, Dynamic typing is a type of typing where you don’t have to decide what the type of a variable is when you make the variable.

Examples of dynamically typed programming languages include JavaScript,Python, PHP,Ruby, etc…

Example in Python:

$ name = “John Doe” // $name is now of type string
$ age = 15; // $age is now an integer
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Advantages of Dynamic Typing

Easier to write. Declaring variable types can be a pain, especially in multi-line statements when you need to declare the same type multiple times.
Easier to refactor code. Renaming variables that are dynamically typed does not require changing their declaration or type annotation; with static typing, you would have to change all references in the codebase for the variable’s type.
Faster development time. Without needing to declare variable types, you can simply start coding and then run your code.


Conclusion

Static typing is undeniably powerful, with its ability to avoid runtime errors. Dynamic typing is easier to integrate, and doesn’t require extensive changes to existing code. Which one wins? It depends on how you want to approach your project. Choose wisely — the type system you choose today can affect your code for years to come.

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