Format Specifiers in C Language
Format specifiers can be divided into seven groups.
- Integer Format Specifiers
- Floating-Point Format Specifiers
- Character & String Format Specifiers
- Pointer Format Specifier
- Special Format Specifiers
- Format Specifiers for scanf()
- Field Width & Precision
Integer Format Specifiers in C Language
| Specifier |
Description |
Example |
| %d |
Signed decimal integer |
int a = 10; |
| %i |
Signed integer (decimal, octal, hex) |
int b = 015; |
| %u |
Unsigned decimal integer (positive integer) |
unsigned int a = 20; |
| %o |
Octal integer |
15 → 17 |
| %x |
Hexadecimal (lowercase) |
255 → ff |
| %X |
Hexadecimal (uppercase) |
255 → FF |
| %ld |
Long signed decimal |
long d = 999999; |
| %lld |
Long long signed decimal |
long long e = 123456789; |
| %lu |
Unsigned long |
unsigned long f = 12345; |
| %llu |
Unsigned long long |
unsigned long long g = 987654321; |
Floating-Point Format Specifiers in C Language
| Specifier |
Description |
Example |
| %f |
Float |
10.25 |
| %lf |
Double |
double d = 20.123; |
| %Lf |
Long double |
long double ld = 30.456; |
| %e |
Scientific notation (lowercase) |
3.14e+03 |
| %E |
Scientific notation (uppercase) |
3.14E+03 |
| %g |
Uses %f or %e based on value length |
printf("%g", 123456.0); |
| %G |
Uses %f or %E based on value length |
printf("%G", 123456.0); |
Character & String Format Specifiers in C Language
| Specifier |
Description |
Example |
| %c |
Single character |
char ch = 'A'; |
| %s |
String |
char str[] = "Hello"; |
Pointer Format Specifier
| Specifier |
Description |
Example |
| %p |
Address of a variable |
int a = 10; printf("%p", &a); |
Special Format Specifiers in C Language
| Specifier |
Description |
Example |
| %n |
Stores number of printed characters into a variable |
printf("Hello%n", &x); |
| %% |
Prints % symbol |
printf("50%%"); |
Format Specifiers for scanf() in C Language
| Specifier |
Description |
Example |
| %d |
Read integer |
scanf("%d", &a); |
| %f |
Read float |
scanf("%f", &b); |
| %lf |
Read double |
scanf("%lf", &c); |
| %c |
Read character |
scanf("%c", &ch); |
| %s |
Read string (up to space) |
scanf("%s", str); |
Field Width & Precision
| Format |
Meaning |
Example |
| %5d |
Print integer in width 5 |
printf("%5d", 10); |
| %05d |
Pad with leading zeros |
printf("%05d", 10); |
| %.2f |
Print 2 digits after decimal |
printf("%.2f", 10.256); |
| %8.3f |
Width 8, precision 3 |
printf("%8.3f", 10.25678); |
