Static typing and dynamic typing are two common terms in the programming world. If you are planning to venture into this arena, one day you will have to choose between the two types of languages. Knowing the difference between them will help you to make the right choice when you want to build advanced systems. But, have you ever bothered to know what they mean or when they are used? In this article, we are going to look at the difference between static and dynamically typed programming languages.
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Meaning of “Typed”
First things first. Before we proceed to dissect the differences between these two types of programming languages, let’s find out the meaning of the term “typed”. Typed in this context has nothing to do with the computer’s keyboard and a text editor. Type in the world of programming refers to the data types and the manipulation that is allowed in a specific programming language. It describes the structure of the data and how they are stored in the memory. Strings, integers, Boolean, and Float are all types. In terms of programming languages, we can categorize typing into Statically typed or dynamic typing.
Now that we have cleared the air, let’s proceed and unmask these two typing.
Also, Read: Difference between Front-end, Back-End, and Middleware developers
What is static typing?
Static typed is a programming language in which a programmer must declare the variables clearly before using them. As a programmer, you don’t have to define the variables before they are put into use. The most popular static typed programming languages are C, C++, and Java. You can also read more about it on Webinarcare.
It is important to note that although you can cast a variable in the statically typed programming language, it will not be converted into another type of variable. Instead, it will only be read in a different manner. In these programming languages, using a variable if you have not declared it will result in an error.
What is Dynamic Typed?
Dynamic typed is a complete opposite of the statically typed programming language. In dynamic typed, all the variables must be defined before they are used. The good thing about dynamic typed is you don’t have to declare these variables. Also, the variables don’t have to be typed into a particular type.
For example, if you are planning to use the variable x, you must assign it a value before you use it. Some of the popular dynamic typed programming languages include Python, JavaScript, Perl, Ruby, and Lua.
Compiled vs Interpreted
Another key difference between static vs dynamic programming languages is that one is compiled while another one is interpreted. Statically typed programming languages are compiled when executed. Each line of code is translated before the run-time. On the other hand, dynamically typed programming languages are interpreted when executed.
Type Checking
Another difference is based on the time when the types (specific variables) are checked. In statically typed programming languages, types are checked before the run-time. If the code is found to be having an unsuitable type, an error will be thrown before the run-time. For dynamically typed programming languages, types are checked during the execution of the code. Even if the line of code has a mistake, an error won’t be thrown. Instead,
Performance
The difference between the two types of programming languages also lies in the performance. Statically typed programming languages have better performance than their dynamic counterparts. This is because these languages have the full knowledge of types. This allows the machine to focus on optimizing the codes.
The performance of statically typed languages remains good at run-time as there is no need of type-checking. This is the opposite of dynamic languages as the codes have to be type-checked during run-time.
Error checking
Static typed programming languages catch errors during the early stages of programming. It leaves no room for type errors as you continue coding. Static programming prevents the changing of variables in the program. This feature makes them ideal for long programs. Dynamic programming catches errors during the execution. In doing so, it may slow down the programming process.
Flexibility
Dynamic typing is more flexible than static programming. This is because it allows variables to change types. On the other hand, static programming languages don’t allow the changing of variable types.
From these differences, you can see that there is no actual winner. Both the static and dynamic typed programming languages have their unique strengths and weaknesses. The final decision depends on your preferences.
Not quite…
The types is the semantics of a string of bits, well, consider “float” or “real” – what is the base of the mantissa used? All of this is in the hardware now. And then you code in character strings, where the number is just a sequence of digits, but in what number system: 2,8, 10, 16 or 35 to name a few.
You cannot store an “int” in a character string, or a boolean or a float or complex numbers.
The lax type checking is related to SIMULA and C++, where SIMULA introduced “virtual” in the meaning “as if, in effect” – and allowed you to create types and subtypes for whatever you wanted, well to some extent. In C++ they removed all constraints, and then got into tons of problems, one of them “run-time verification and explicit or implicit conversion / casting”. In C++ the compiler will try to verify classes used as types – “aggregates” and this can be done if all definitions of a bit string is available.When it is not made available to the compiler, this will warn but allow use. In Simula, the language will only allow “virtual” classes inside scope, and then they must be nested, and organised as subtypes using one another as “templates”.
BASIC is an interpreted programming language but here there is 2 types: numbers and strings – no Integer. Data can be used as needed. The problem with this is that you believe you use the same variable, but a misspelling makes them different.
“Compile time verification” is when the compiler can verify e.g. use “#include” header files with definitions to check and verify the code you write. Then nothing will be tried checked while the code executes.
With everything as strings, the verification of the strings passed can be done when the code is executed: you parse the string to confirm that a number just contain digits and signs and decimal point and is nil terminated.
In the Simula, Smalltalk, C++ there is no discussion about run-time verification of the classes and their use, it is taken for granted that is managed by the compiler, but the the “virtual” entities, code could be amended to verify and confirm use.