What are the legal keywords in C language?

C language legal keywords are: 1. char, declares character variables or functions; 2. double, declares double-precision variables or functions; 3. do, the loop body of a loop statement; 4. goto, unconditional Jump statement; 5. static, declare static variables.

The legal keywords in C language are:

1. Key words about data types Words (12)

(1) char: declare character variable or function

(2) double: declare double precision variable or function

(3 ) enum: declare enumeration type

(4) float: declare floating point variable or function

(5) int: declare integer variable or function

(6 ) long: declare a long integer variable or function

(7) short: declare a short integer variable or function

(8) signed: declare a signed type variable or function

(9) struct: declare a structure variable or function

(10) union: declare a union (union) data type

(11) unsigned: declare an unsigned type variable or function

(12) void: Declare a function with no return value or parameters, declare a typeless pointer (basically these three functions)

2. Keywords about control statements

A. Loop statement

(1) for: a loop statement

(2) do: the loop body of the loop statement

(3) while: The loop condition of the loop statement

(4) break: Jump out of the current loop

(5) continue: End the current loop and start the next cycle

B. Conditional statement

(1)if: conditional statement

(2)else: conditional statement negation branch (used with if)

(3)goto: unconditional jump Switch statement

C, switch statement

(1)switch: used for switch statement

(2)case: switch statement branch

(3) default: "Other" branch in the switch statement

D, return statement

return: subroutine return statement (can take parameters or not)

3. Keywords about storage types

(1)auto: It is generally not used to declare automatic variables

(2)extern: The declared variable is declared in other files ( It can also be regarded as a reference variable)

(3)register: declare the accumulator variable

(4)static: declare the static variable

4, other types Keywords

Related learning recommendations: C video tutorial

Extension Information:

Characteristics of C language:

The notable feature is the separation of code and data, that is, each part of the program is independent of each other except for necessary information exchange. This structured approach can make the program hierarchy clear and easy to use, maintain and debug. C language is provided to users in the form of functions. These functions can be easily called and have a variety of loops and conditional statements to control the program flow, thus making the program completely structured.

Grammatical restrictions are not too strict, and programming freedom is large: Although C language is also a strongly typed language, its syntax is relatively flexible, allowing program writers to have greater freedom.

Allows direct access to memory addresses and operations on hardware. Because the C language allows direct access to memory addresses and can directly operate on the hardware, it has both the functions of a high-level language and many functions of a low-level language. It can operate on bits, bytes and addresses like assembly language, and this The three are the most basic working units of the computer and can be used to write system software.

Related learning recommendations: Programming video

The above is the detailed content of What are the legal keywords in C language?. For more information, please follow other related articles on the PHP Chinese website!