C Language-scanf function

1) scanf function, is a standard input function

is a blocking function: When using scanf, the program waits for user input, and if you do not enter the content, the program no longer executes

Function: Receive the content that is lost from the keyboard

2) Use the format:

Compare printf

printf ("Format control string", variable list);

scanf ("Format control string", "Address" list of variables)

The address of the variable: the first address of the variable

method to get the first address of a variable: & variable Name

printf ("A =%d\n", a);

scanf ("%d", &a);

3) Format Control

%d receives an integer

%f Receive real numbers

%c receives characters

...

4) The use of scanf function attention point

(1) When using the SCANF function to receive an "integer", enter a space before entering the Data tab return

The scanf function ignores

(2) scanf function when entering data, use carriage return as Terminator

(3) But when you enter a character, it's a bit of a problem.

Example 1

scanf ("%d%d%d", &a,&b,&c);

If you enter in the control area: 4 5 7-"The space will be ignored, printed or 4,5,7

Example 2

scanf ("%d%c%d", &a,&b,&c);

If you enter:4c7-> in the control area, print is 4,c,7

However, if you appear in front of the character < space >< comma >< carriage return, the structure is wrong,

If you enter in the control area: 4 C7->&a will take away 4,&b will take away < space >,&c will take C, and then print it in ASCII code

This is an easy mistake to make (because < spaces > and < Enter >< comma > are characters)

The buffer is where the input is waiting,

C Language-scanf function