Basic fast over C language II: What is the keyword identifier system reserved word variables and constants [common for each language]

Source: Internet
Author: User

0, actually studied for so long. These keyword identifiers system reserved words I have already divided the classification.

For this reason I deliberately Baidu under these traditional concepts. Oh.

Reserved words:

Auto Break case Char Const
Continue default do double else
enum extern float for Goto
If int long redister return
Short signed sizeof static struct
Switch typedef Union unsigned void
volatile while

These English words please be sure to read will write know meaning. Because it's basic. Requires forced memory.

What the? You said you couldn't? Yes. Then don't carry it. See my tutorial to let you learn sooner or later.

1. What is a keyword

The keyword is nothing more than a pre-defined word in the system. You're right. You must not use these words as variable names and function names when you are programming. Remember that compilation must not pass.

You say your English words are poor? I'll teach you.

For example: You want to declare a variable you can be like this. Temp demo. What the?  You don't understand English?  What about pinyin? Linshi. Zhanshi. Ceshi. Yes, you can. But please try not to use the latter.

2. What is an identifier

When you define variables, remember that you must not start with a number. can be underlined but not allowed by other symbols. The numbers don't start on the back, it's okay.

But except for the underscore. Other symbols are not allowed. But:& * && | | & | These symbols are explained later. Pointer manipulation and bitwise operations. 0101010101010 you know that.

3, what is the system reserved word

Similar to the keyword. A system reserved character cannot be used as the name of a function that defines a variable name.

4. Variables and Constants

1. Variables:

is actually a container. He is of a type.  For example: Each wine is bottled in a different way. A variable is an amount that can be changed. He can be empty and can change data frequently.

But he also has the capacity to store. Will cause a memory leak. Defining a variable is an unknown value in the C language. Need to initialize for example: int a=0;

2. Constants:

is actually a container.  But he was sealed. Can only be placed at the beginning of initialization. Cannot be changed in the future.

Basic fast over C language II: What is the keyword identifier system reserved word variables and constants [common for each language]

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