ios-(1) C language Introduction

1. Why you should learn the C language first

* OC based on C.

* OC and C's thought and grammar are different in many places, and OC can be mixed with C.

* C is the classic of all programming languages, many high-level languages are derived from C language, such as c++,c#, Objective-c, Java and so on.

2. Brief History

* The C language was invented in 1972 and was first used to rewrite the Uinx operating system (Unix was written primarily in assembly language, which laid the foundation of the operating system).

* With the success of Unix operating system, C language has also been greatly promoted, has been used in large, medium and small, micro-host, is still the world's most popular, the most widely used in one of the most advanced programming languages.

* C language is a process-oriented language, non-object-oriented language.

3. Features

* Rich operator

* Rich data types

* Can operate the hardware directly

* Efficient Target Code

* Portability is good

4. Main uses

* Write system software, graphics processing, SCM program, embedded system development.

* Write a game plug-in.

* Write iOS programs.

* ......

5. Version issues

* In 1983, the U.S. National Bureau of Standards (American Nation Standards Institute, abbreviated as ANSI) set up a committee to begin working on the C language standard.

* 1989 C language Standard is approved, this version of the C language standard is commonly referred to as ANSI C.

* In 1999, ISO also revised the C language standard, on the basis of the basic retention of the original C language features, in response to the needs, added some functions, named C99.

* December 8, 2011, ISO officially publishes the new international Standard for C language: C11.