C format specifiers

Absolutely! In C, format specifiers are used in functions like printf() and scanf() to tell the compiler what type of data you're working with.

complete list of commonly used format specifiers, along with what they do and an example for each:

Basic Format Specifiers

Specifier	Data Type	Description	Example Code	Output
%d	int	Signed decimal integer	printf("%d", 42);	42
%i	int	Same as %d in printf; base-detect in scanf	scanf("%i", &x); (0x10 = 16)	Depends
%u	unsigned int	Unsigned decimal integer	printf("%u", 42);	42
%f	float/double	Decimal floating-point (6 digits)	printf("%f", 3.14);	3.140000
%lf	double	Reads a double in scanf()	scanf("%lf", &d);
%c	char	Single character	printf("%c", 'A');	A
%s	char[] (string)	String of characters	printf("%s", "Hi");	Hi
%x	int	Unsigned hexadecimal (lowercase)	printf("%x", 255);	ff
%X	int	Unsigned hexadecimal (uppercase)	printf("%X", 255);	FF
%o	int	Octal (base 8)	printf("%o", 10);	12
%p	Pointer address	Memory address	printf("%p", ptr);	0x7ffee...
%%	Literal %	Prints a percent sign	printf("%%");	%

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🧠 Advanced / Less Common Specifiers

Specifier	Data Type	Description	Example
%e / %E	float/double	Scientific notation	printf("%e", 123.45); → 1.234500e+02
%g / %G	float/double	Shorter of %f or %e	printf("%g", 123.45); → 123.45
%ld	long int	Long decimal integer	printf("%ld", 123456789L);
%lld	long long int	Longer integer	printf("%lld", 123456789LL);
%zu	size_t	Unsigned size type	printf("%zu", sizeof(x));

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💡 Examples Together

#include <stdio.h>

int main() {
    int i = 10;
    float f = 3.1415;
    char c = 'A';
    char str[] = "Hello";
    printf("int: %d\n", i);
    printf("float: %f\n", f);
    printf("char: %c\n", c);
    printf("string: %s\n", str);
    return 0;
}

Output:

int: 10
float: 3.141500
char: A
string: Hello

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✨ Tips

• Always match the format specifier with the correct data type — or you’ll get garbage output or runtime errors.
• Use \n for new lines in printf().
• Use scanf() carefully — wrong specifier can cause serious bugs.