First of all, what are all these words - Statically - Dynamically - Strongly - Weakly Typed Languages? This is how you can classify programming languages: Statically typed vs Dynamically typed programming languages Strongly typed vs Weakly typed programming languages. We will understand what these terms mean so you don't have to look them up in your next . flame war So let’s dive right in : Type Checking It’s the process of verifying and enforcing the constraints of types. Usually performed by the compiler or interpreter at compile or run time. For instance you can’t divide a string by a floating point number (if you can, please don't). In simpler terms, type checking is just looking at variables and their types and then saying does this expression make sense. So, now we know what type checking is, understanding these terms is really simple. In type checking happens at compile time. Whereas, in , type checking happens at run-time. statically typed languages dynamically typed languages What Does That Mean For You? All variable types have to be explicitly stated as this information is required at compile time. For example in Java Type declaration Static: float f = 0.5; Explicit declaration is not required as type is assigned to a variable at runtime. For example in Python Dynamic: f = 0.5 Do more processing at compile time but give better run-time performance. Performance Static: More efficient compiler/interpreters, but type-checking at run-time affects performance. Dynamic: Is less prone to runtime errors but provide less flexibility to programmer. Flexibility and Errors Static: Provides more flexibility but more prone to runtime errors. Dynamic: A quick hack to remember what are statically typed and dynamically typed language, is to call them by their full names Remember It ==> Statically type-checked languages. ==> Dynamically type-checked languages. The language cloud. Courtesy: Mayank Bhatnagar . But What are Strongly Typed and Weakly Typed Languages? It’s a spectrum* (disclaimer at the bottom). So, we will just go ahead and learn the terms the way they are often used. In once a type is assigned to a variable say at run time or compile time, it retains that type and can’t be intermingled in expressions with other types easily. Strongly typed languages For example in Python data = “string1” //Type assigned as str at runtime data = 5 //Type assigned as int at runtime data = data + “string2” //Type-error str and int can’t be concatenated Whereas, in , once a type is assigned to a variable say at run-time or compile-time, it can be intermingled in expressions with other types easily. Weakly typed languages For example in Javascript $data = “string1” //Type assigned as str at runtime $data = 5 //Type assigned as int at runtime $data = $data+“string2” //str and int get concatenated Conclusion Type checking ensures that correct variable types are part of an expression. In Statically type-checked languages, type checking happens at compile time, whereas in dynamically type-checked languages, type checking happens at run-time. Strongly typed languages have a stronger type-check and enforce the type assigned (at compile or run time), whereas, weakly typed languages have a weak type-check and allows expressions between various different types. (Fun?) Disclaimer If you go into the nitty gritty and try to find right answer, you will come back (exactly!). THE discombobulated Turns out, there is of these terms agreed throughout the industry. It’s a spectrum. no official demarcation But the terms still get thrown around a lot. So, I went digging. calls Java a strongly typed language. Java Language Specification But uses no such term. The C Programming Language First Edition References medium.com/p/magic-lies-here-statically-typed-vs-dynamically-typed-languages docs.oracle.com/javase/specs/jls/se8/jls8.pdf archive.org/details/TheCProgrammingLanguageFirstEdition/page/n7 stackoverflow.com/a/430414/4693983 stackoverflow.com/a/1520342/4693983 blogs.msdn.microsoft.com/alfredth/2012/02/17/how-to-start-a-computer-science-flame-war/ merriam-webster.com/dictionary/discombobulate medium.com/@haydnjmorris/page-2-dynamically-typed-vs-statically-typed-languages-e507ac463496 Find me on Twitter, Facebook, Linkedin, Quora, Github, Medium, Gmail @jarpit96
