Ok, let's review the previous chapters, all the main() function just followed some variables and equation, for example
main()
{
int a = 1;
int b = 2;
int c = 0;
c = a + b;
}
We know the result is 3 ,surely c equals 3. Actually when this program is complied and linked , the variable c is 3 , but if a and b are big numbers ,like "a = 246524" and "b = 34532465", can you tell me the result immediately as you see that? I don't know whether u can or not, but i can't. Because i'm not a genius. But actually , when we write them as a program, then compile and linked it. The result just hold in the variable c as above program. My pc knows the result, but i don't . How can i let the pc tell me the the result?Let's us use the function of printf().
The printf() function is one fo the predefined standard C functions. The basic purpose is used to print some useful information between the quotation marks like table belows , printf() function just output these characters.
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printf() function output
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printf("Hello everyone!"); Hello everyone!
printf("ERROR!"); ERROR!
printf("a: b: c:"); a: b: c:
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At "Let us learn C in Code <3>" we have refer with some special characters which are composed by two characters but actually represent one character. So if we let the printf() function output these special characters , what happened? Don't afraid there is not boooom, u can't destroy ur computer ,too. Just try them, before doing that let's list these special constant characters ,please refer to the below table.
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constant meaning
------------------------------------------------
'\n' newline
'\a' alert (sound)
'\r' carriage return
'\0' null
'\"' double quote
'\'' single quote
.... ....
---------------------------------------------
I don't list all of the special characters, these list above are used frequently. Just try them in our program , for example
main()
{
int x = 2;
int y = 0;
y = (x*x) +(2*x) +1
printf("Now,x equal 2 and the value of y is \n\a");
}
Time limited, the above program is just the one answer of the "Let us learn C in Code <4> data type" mentioned. Have a nice day every one, I hope u enjoy it. See you next chapter!