Go and the Hello world revolution

Go language

In 2007, three technical experts wanted to design a new language with the goal of becoming the C language in the Internet and multi-core era.
In mid-2008, the feature design of the language was completed, and work began on implementing the compiler and runtime. Russ Cos joined
In 2009, Go began to gradually stabilize. In September of the same year, Go was officially released and open sourced.

Go's genetic map

Concurrency features

It evolved from the CSP theory released by Hoare of Bell Labs in 1978.
The CSP concurrency model has been gradually improved in programming languages such as Squeak/Newsqueak and Alef, and is moving toward practical applications.

Erlang is another implementation of CSP theory.

Object-oriented, packages, interfaces

The Pascal language designed by Niklaus Wirth, and related programming languages derived from it.
The concept of package, package import and declaration syntax, etc. mainly come from the Modula-2 programming language. The
declaration syntax of the methods provided by the object-oriented method comes from the Oberon programming language.

GO has developed its own unique implicit interface that supports duck object-oriented types and many other features.

other

iota is borrowed from the APL language
Lexical scope, nested functions, from Scheme language

Slicing: provides efficient random access for lightweight dynamic arrays
defer

Hello World

B language

When Ken Thompson was young, he designed a general programming language called B language at Bell Labs to assist in the development of Unix systems.

//定义全局变量，设定要输出的内容
//每个变量的长度，必须对齐到4字节，和写汇编语言一样
a 'hell';
b 'o, w';
c 'orld';

//多次调用putchar函数输出字符
//!*n表示换行
main(){
   
    
    
    extrn a,b,c;
    putchar(a);putchar(b);putchar(c);
    putchar('!*n');
}

Language B is simple, has limited functions, lacks flexible data types, and is difficult to use.

In order to provide rich types, Ken's colleague Dennis Ritchie developed the C language based on the B language and rewrote UNIX. So far, C language has become one of the commonly used programming languages.

C language

Early days

main(){
   
    
    
    printf("hello, world")
}

/*
说明
1. main函数没有明确的返回值类型，默认为int类型
2. printf函数默认不需要导入函数声明即可使用
3. main没有明确返回语句，但默认返回0
*/

Functions do not need to write return values
Function parameters can be ignored
There is no need to include header files when using printf

1978, "C Programming Language·1st Edition"

main(){
   
    
    
    printf("hello, world\n")
}

Added line breaks, more !*nconcise than

1988, "C Programming Language·2nd Edition"