These are format characters

Use different format characters when outputting different data

%d is used to output decimal integer data The actual length is output

%c is output in character form, only one character is output

%f is output single or double precision degree in decimal form, implicitly outputting 6 decimal places< /p>

There are many more, such as %s (output string) and so on

So how to use it?

For example, when printf outputs data

int n=5;

printf("%d",n);

This way It's output.

Printf function format characters:

In C language, different format characters are used for different types of data. The following format characters are commonly used:

(1) d format character. Used to output decimal integers. There are several usages:

1. %d, output according to the actual length of integer data.

2. %md, m is the width of the specified output field.

3. %ld, output long integer data.

(2) o format character, output integer in octal integer form.

(3) x format character, output integers in the form of hexadecimal numbers.

(4) The u format character is used to output unsigned data, that is, unsigned numbers, output in decimal form.

(5) c format character, used to output a character.

(6) s format character, used to output a string.

(7) The f format character is used to output real numbers (including single and double precision) in decimal form.

(8) e format character, output real numbers in exponential form.

(9) The g format character is used to output real numbers. It automatically selects the f format or the e format according to the size of the value (the selected output is the one with a smaller width), and does not output meaningless of zero.

(10) %[scanfset]:

scanfset has two forms: one is a scanset starting with a non-"^" character, which means that it will match when reading the string For all characters that appear in scanfset, the input ends when encountering characters not in scanfset; another form is scanfset starting with the "^" character, which means that when reading a string, all characters that do not appear in scanfset will be matched. , ends when character input in scanfset is encountered.