What is the difference between static and dynamic languages?

The difference between static language and dynamic language:

Difference 1:

A static language is a language in which the data type of variables can be determined at compile time. Most statically typed languages ​​require that the data type must be declared before using variables; for example, C/C is a typical representative of statically typed languages, and other statically typed languages ​​include C#. , JAVA, etc.

Dynamic languages ​​are languages ​​that determine data types at runtime. There is no need for a type declaration before a variable is used. Usually the type of a variable is the type of the value to which it is assigned; Python and Ruby are typical dynamically typed languages, and various other scripting languages ​​such as JavaScript are also dynamically typed languages.

Difference 2:

Static type languages ​​will perform type matching checks when compiling, so variables cannot be assigned values ​​of different types. In order to solve this problem, statically typed object-oriented languages ​​usually achieve polymorphic effects through upward transformation technology.

The variable types of dynamically typed languages ​​are variable during runtime, which means that the polymorphism of objects is inherent. Whether an object can perform a certain operation only depends on whether there is a corresponding method, not whether it is an object of a certain type.

Difference 3:

Advantages of static language:

Due to the mandatory declaration of types, the IDE has strong code awareness, so in In implementing complex business logic, developing large-scale commercial systems, and applications with long life cycles, system development is guaranteed by relying on IDE;

Because static languages ​​are relatively closed, third-party development packages are not suitable for The invasiveness of the code can be minimized;

Advantages of dynamic language:

The number of codes written is less, it looks more concise, and you can focus more on business logic. Although not distinguishing between types can make the program difficult to understand in some cases, overall, the smaller the amount of code and the more focused on logical expression, the more helpful it is to read the program.

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