programing language

The development of programming language

1. Machine oriented machine language （ Low level language ）

2. Machine oriented assembly language （ Low level language ）

3. Process oriented high-level language

4. Object oriented high level language

Low level language   and   High-level language

Low level language ：

machine language ：

Computer hardware can only recognize “ To break off ” and “ closed ” Two physical states , That is to say 0 and 1. Using machine instructions is the most efficient , Because there is no need to translate the instructions . But machine language is not human friendly , A large string 0 and 1, It's hard to recognize and remember , And easy to make mistakes , But for machines , Seconds understand

assembly language ：

Assembly language uses mnemonics that are easy for human to remember and recognize to represent 0 and 1 Instructions , Also known as symbolic language

such as AND For addition

High-level language ：

Use characters that are easy to recognize and remember as keywords , It is also closer to the human way of thinking , Easy to write, easy to read and write , More efficient development

High level languages are portable , Make small or no changes , You can run the code on computers of different platforms .

summary ：

The lower a language is, the more machine friendly it is , The more consistent with the way of thinking of the machine , Therefore, the implementation efficiency is high .
The more advanced the language is, the more friendly it is to human beings , The more consistent with the human way of thinking , Therefore, the development efficiency is high .

The following are all for high-level languages ： 

Compiler language   and    Explanatory language

Compiler language ：

Call a pre - made one “ compiler ” The machine language program of is installed in the computer , When a high-level language program needs to be executed , The compiler puts the whole “ High level language source program ” Translate into “ The object program of machine language ”

Explanatory language ：

After the high-level language enters the computer , The interpreter scans and interprets , Input sentence by sentence, translate sentence by sentence , The computer executes line by line , Does not produce the target program

Java

Dynamic type language   and   Static type language

Dynamic type language ：

Do data type checking only during runtime

flexible , Fast development speed , studies of the Book of Changes , But you can't immediately give an error and further optimize the code

Python、Ruby、Erlang、JavaScript、swift、PHP、Perl

Static type language ：

When you write code, make sure the data type of the variable

C、C++、C#、Java、Object-C、Go

  Strong type language   and Weak type language

Strong type language ：

Mandatory type definition

Types are more secure

Python,Java

Weak type language ：

Can treat one data type as another , That is, data types can be converted at any time , flexible

Everything is subject to running , How is it convenient