Static type and dynamic type

pythonconquerstheuniverse Static vs. dynamic typing of programming languages

Updated 2010-10-20 — added a bit more information about Boo’s type inferencing. Updated 2012-04-08 — This post is an appendix to a post comparing Java and Python. Some comments on this post are actually comments on that other post.

There is widespread confusion or disagreement about the meanings of the words static, dynamic, strong and weak when used to describe the type systems of programming languages.

Here is a description of the way (or at least one of the ways) these terms are most commonly used. | | | | ------------------------------------------------------------ | ------------------------------------------------------------ | | In a statically typed language, every variable name is bound both to a type (at compile time, by means of a data declaration) to an object.The binding to an object is optional — if a name is not bound to an object, the name is said to be null.*Once a variable name has been bound to a type (that is, declared) it can be bound (via an assignment statement) only to objects of that type; it cannot ever be bound to an object of a different type. An attempt to bind the name to an object of the wrong type will raise a type exception. | In a **dynamically typed language*, every variable name is (unless it is null) bound only to an object.Names are bound to objects at execution time by means of assignment statements, and it is possible to bind a name to objects of different types during the execution of the program. | | | |

Here is an example.

In a statically-typed language, the following sequence of statements (which binds an integer object, then a string object, to the name employeeName) is illegal. If employeeName had been declared to be an int, then the second statement would be illegal; if it had been declared to be a String, then the first statement would be illegal. But in a dynamically-typed language this sequence of statements is perfectly fine.

`employeeName = 9 employeeName = "Steve Ferg"`

Python is a dynamically-typed language. Java is a statically-typed language.

Is it possible to have a dynamically typed language without duck typing? [closed]

static vs dynamic vs strong vs weak vs duck typing

思考 : strong type和duck type是否冲突？

https://devopedia.org/duck-typing

C++ static type and runtime type

C++是典型的区分static type和runtime type的语言。

在文章A polyglot's guide to multiple dispatch中，提出了static type和dynamic type的概念。