Programming languages datatype

Programming languages datatype

statically typed language
A language in which types are fixed at compile time. Most statically typed languages enforce this by requiring you to declare all variables with their datatypes before using them. Java and C are statically typed languages.
dynamically typed language
A language in which types are discovered at execution time; the opposite of statically typed. VBScript and Python are dynamically typed, because they figure out what type a variable is when you first assign it a value.
strongly typed language
A language in which types are always enforced. Java and Python are strongly typed. If you have an integer, you can't treat it like a string without explicitly converting it.
weakly typed language
A language in which types may be ignored; the opposite of strongly typed. VBScript is weakly typed. In VBScript, you can concatenate the string '12' and the integer 3 to get the string '123', then treat that as the integer 123, all without any explicit conversion.

So Python is both dynamically typed (because it doesn't use explicit datatype declarations) and strongly typed (because once a variable has a datatype, it actually matters).

Weak typing - Wikipedia, the free encyclopedia

In computer science, weak typing (a.k.a. loose typing) is a property attributed to the type systems of some programming languages. It is the opposite of strong typing, and consequently the term weak typing has as many different meanings as strong typing does (see strong typing for a list and detailed discussion).

One of the more common definitions states that weakly typed programming languages are those that support either implicit type conversion (nearly all languages support at least one implicit type conversion), ad-hoc polymorphism (also known as overloading) or both. These less restrictive usage rules can give the impression that strict adherence to typing rules is less important than in strongly typed languages and hence that the type system is "weaker". However, such languages usually have restrictions on what programmers can do with values of a given type; thus it is possible for a weakly typed language to be type safe. Moreover, weakly typed languages may be statically typed, in which case overloading is resolved statically and type conversion operations are inserted by the compiler, or dynamically typed, in which case everything is resolved at run time.