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This article mainly introduces "how to use C language escape characters". In daily operation, I believe many people have doubts about how to use C language escape characters. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful for you to answer the doubts about how to use C language escape characters! Next, please follow the editor to study!

What is an escape character

Today, let's take a look at escape characters, which, as the name implies, change their meaning.

Now learn about these characters:

Escape character interpretation

\? Used when writing multiple question marks in succession to prevent them from being parsed into three-letter words

\ 'used to represent character constants'

\ "used to indicate double quotation marks inside a string

\\ is used to represent a backslash to prevent it from being interpreted as an escape sequence.

\ a warning character, beep

\ b backspace character

\ F Feed character

\ nWrap

\ r enter

\ t horizontal tabs

\ v Vertical tab character

\ ddd ddd represents 1 to 3 octal numbers. Such as:\ 130X

\ xdd dd represents 2 hexadecimal digits. Such as:\ x300

Why do you use these escape characters

Let's talk about the three-letter word (in the past, the compiler in use no longer uses it, so it can't be demonstrated), if we want to print some characters, such as?), the corresponding symbol in the three-letter word is]

?)-- >]

? (- > [

It means what you wanted to print. These three symbols, but in the eyes of the compiler, they are], so it will print out for you], not?)

So you want to print it out?) What should I do?

We just need to put?) Add one before it.

That is,

\?) / / escape character\?

Can it make? Become not in the three-letter word? What makes it honest is a?, so the compiler will not print out]

The three-letter word is really too old, but this grammar can't go away, so we use escape characters all the time.

Here's a summary of the formats we use to print.

/ /% d-print integer

/ /% c-print character

/ /% s-print string

/ /% f-print data of type float

/ /% lf-print data of type double

/ /% zu-print the return value of sizeof

If we want to print a character, it looks like this:

# includeint main () {printf ("% c",''); / / Let's print 'return 0;}

Running result:

An error has occurred.

So what is the reason for the mistake?

Let's take a look at this. When printf recognizes, recognize the first one, and then recognize another one. Ah, it ends here, just like recognizing this character. As long as you recognize a pair, the printing will end, but there is a third 'which is superfluous and makes a mistake.

So, we use the escape character\', so that'is no longer a pair of'w' inside', like the above?) The same

Verify:

# includeint main () {printf ("% c",'\'); / / Let's print the 'return 0;} / / escape character\'

The result of the operation:

Let's continue to learn about escape characters.

We print strings in two forms:

# includeint main () {printf ("% s\ n", "abcdef"); / / form 1 printf ("abcdef"); / / form 2 return 0;}

The second form cannot be printed directly like this:

Printf (2123456) / / incorrect

If we add a\ 0 in the middle of the abcdef, but because it represents a line break, we need to invalidate it. Let\ 0 be\ 0. There is no other meaning. We just need to do this:

# includeint main () {printf ("% s\ n", "abc\\ 0def"); / / form-printf ("abc\\ 0def"); / / form II return 0;} / / escape character\\

The escape characters in the table above are all used like this.

To practice a problem.

# include # include int main () {printf ("% d\ n", strlen ("c:\ test\ 121")) return 0;}

What is its output?

Answer analysis:

Strlen: gets the valid length of the string, excluding'\ 0'

"c:\ test\ 121": in this string,\ t is a transferred character, horizontally tabulated, skipping to the position of the next tab; and\ 121represents a character, which is treated as an octal array, converted to 81 after decimal, and the job is a character with an ASCII code value, that is, the character'Q', so the above string is actually" c: esty "with only 7 valid characters.

If we really want to print c:\ test\ 121, we need to change it to c:\\ test\\ 121so that we can print it out.

With regard to escape characters, we only need to remember the special ones. There is no need to remember all of them. We will use some in the future.

At this point, the study of "how to use escape characters in C language" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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