Format specifiers in C

The format specifiers are used in C for input and output purposes. Using this concept the compiler can understand that what type of data is in a variable during taking input using the scanf() function and printing using printf() function. Here is a list of format specifiers.

These are the basic format specifiers. We can add some other parts with the format specifiers. These are like below −

• A minus symbol (-) sign tells left alignment

• A number after % specifies the minimum field width. If string is less than the width, it will be filled with spaces

• A period (.) is used to separate field width and precision

Example

#include <stdio.h>
main() {
   char ch = 'B';
   printf("%c\n", ch); //printing character data
   //print decimal or integer data with d and i
   int x = 45, y = 90;
   printf("%d\n", x);
   printf("%i\n", y);
   float f = 12.67;
   printf("%f\n", f); //print float value
   printf("%e\n", f); //print in scientific notation
   int a = 67;
   printf("%o\n", a); //print in octal format
   printf("%x\n", a); //print in hex format
   char str[] = "Hello World";
   printf("%s\n", str);
   printf("%20s\n", str); //shift to the right 20 characters including the string
   printf("%-20s\n", str); //left align
   printf("%20.5s\n", str); //shift to the right 20 characters including the string, and print string up to 5 character
   printf("%-20.5s\n", str); //left align and print string up to 5 character
}

Output

B
45
90
12.670000
1.267000e+001
103
43
Hello World
Hello World
Hello World
Hello
Hello

We can use these format specifiers for the scanf() function also in the same manner. So we can take the input from scanf() like above how we have printed.