drl 规则语言语法_C语言基本语法规则

drl 规则语言语法

C language syntax specify rules for sequence of characters to be written in C language. In simple language it states how to form statements in a C language program - How should the line of code start, how it should end, where to use double quotes, where to use curly brackets etc.

C语言语法指定了要用C语言编写的字符序列的规则。用简单的语言说明了如何在C语言程序中形成语句-代码行应如何开始，代码行应如何结束，在何处使用双引号，在何处使用大括号等。

The rule specify how the character sequence will be grouped together, to form tokens. A smallest individual unit in C program is known as C Token. Tokens are either keywords, identifiers, constants, variables or any symbol which has some meaning in C language. A C program can also be called as a collection of various tokens.

该规则指定如何将字符序列分组在一起以形成标记。 C程序中最小的单个单元称为C令牌 。令牌可以是关键字，标识符，常量，变量或任何在C语言中具有一定含义的符号。 AC程序也可以称为各种令牌的集合。

In the following program,

在以下程序中

#includeint main()
{printf("Hello,World");return 0;
}

if we take any one statement:

如果我们采取任何一项陈述：

printf("Hello,World");

Then the tokens in this statement are→ printf, (, "Hello,World", ) and ;.

然后，此语句中的标记为→ printf ， ( ， "Hello,World" ， )和; 。

So C tokens are basically the building blocks of a C program.

因此，C令牌基本上是C程序的构建块。

分号`;` (Semicolon `;`)

Semicolon ; is used to mark the end of a statement and beginning of another statement. Absence of semicolon at the end of any statement, will mislead the compiler to think that this statement is not yet finished and it will add the next consecutive statement after it, which may lead to compilation(syntax) error.

分号; 用于标记一条语句的结尾和另一条语句的开头。在任何语句的末尾缺少分号，将使编译器误认为该语句尚未完成，并且将在其后添加下一个连续的语句，这可能导致编译(语法)错误。

#includeint main()
{printf("Hello,World")return 0;
}

In the above program, we have omitted the semicolon from the printf("...") statement, hence the compiler will think that starting from printf uptill the semicolon after return 0 statement, is a single statement and this will lead to compilation error.

在上面的程序中，我们从printf("...")语句中省略了分号，因此编译器会认为从printf开始直到return 0语句后再分号是一个单独的语句，这将导致编译错误。

注释 (Comments)

Comments are plain simple text in a C program that are not compiled by the compiler. We write comments for better understanding of the program. Though writing comments is not compulsory, but it is recommended to make your program more descriptive. It make the code more readable.

注释是C程序中未经编译器编译的纯文本。我们编写注释以更好地理解该程序。尽管写注释不是强制性的，但是建议使程序更具描述性。它使代码更具可读性。

There are two ways in which we can write comments.

我们可以通过两种方式编写评论。

Using // This is used to write a single line comment.

使用//这用于编写单行注释。
Using /* */: The statements enclosed within /* and */ , are used to write multi-line comments.

使用/* */ ： /*和*/内的语句用于编写多行注释。

Example of comments :

评论示例：

// This is a comment/* This is a comment *//* This is a long
and valid comment */// this is nota valid comment

C程序的一些基本语法规则 (Some basic syntax rule for C program)

C is a case sensitive language so all C instructions must be written in lower case letter.

C是区分大小写的语言，因此所有C指令必须使用小写字母书写。
All C statement must end with a semicolon.

所有C语句必须以分号结尾。
Whitespace is used in C to describe blanks and tabs.

C语言中使用空格来描述空格和制表符。
Whitespace is required between keywords and identifiers. We will learn about keywords and identifiers in the next tutorial.

关键字和标识符之间必须有空格。在下一个教程中，我们将学习关键字和标识符。

翻译自: https://www.studytonight.com/c/c-syntax.php

drl 规则语言语法