C language start

（ Some learning experience records , For future review . Please put forward any mistakes , If I can help you , It's a great honor ）

Catalog

One 、C It's a language

Two 、C Widely used in the underlying development

3、 ... and 、C The development of language

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One 、C It's a language

We usually communicate with people in Chinese , I went abroad , Can use English 、 Japanese and other languages , Then the language used to communicate with computers is Computer programming language ,C It is a computer programming language .

Two 、C Widely used in the underlying development

for instance ：

How many parts does a computer need to work properly , The first is hardware , This is the foundation. , Just like our human body ;

The second is the operating system , Like the human brain , The computer has to work , What do you do , How do you do it? , All need the support of the operating system ;

What connects the operating system and hardware is the driver , Like human blood vessels 、 nerve , Like the sound card driver we usually hear 、 Driver. , Network card driver, etc ;

The operating system goes up , The application layer , There are some application software installed here, such as QQ, Yuanshen, etc .

Below the application layer is the bottom layer of the computer .

C Language is especially suitable for low-level development .

3、 ... and 、C The development of language

We know , In the circuit , There are only two states , Electrify / power failure , Or whether there is potential difference . We define energization as 1, Power failure is defined as 0, This produced the first computer language , That's binary language .

Binary language for example 1001010101111 Is the original computer language , By inputting a certain binary sequence to control the work of the computer , This language is inconvenient to use , Sometimes you need to consult the corresponding manual when working （ If you forget the binary sequence of addition ）.

In order to work more conveniently , Later, some fixed sequences were given a code , Suppose the binary sequence that performs addition is 00001111, So let's take 00001111 Write it down as ADD, When we want to use addition , Direct input ADD that will do , The computer read ADD It will be automatically converted into 00001111 This sequence , Form like ADD Of this symbol , We call it Mnemonic symbol , And languages that use mnemonics , We call it assembly language .

In the following , Developed B Language 、C Language and other languages . The purpose is to improve efficiency , Simplify language .

C At the beginning of language development , There must be some deficiencies , And in improving these deficiencies , Different people use different methods ,C Languages have also become diverse , therefore , There is a C standard .