printf Formatters — Quick ReferenceA single-page cheat sheet showing the common format specifiers, length modifiers, flags, width/precision, and examples for printf() in C and C++. (Now includes an interactive simulator!)
| Specifier | Meaning | Example |
|---|---|---|
| %d / %i | Signed decimal integer | printf("%d", 42); |
| %u | Unsigned decimal integer | printf("%u", 42); |
| %o | Unsigned octal | printf("%o", 42); |
| %x / %X | Unsigned hexadecimal (lower/upper) | printf("%x", 42); |
| %f / %F | Decimal floating point | printf("%.2f", 3.14); |
| %e / %E | Scientific notation | printf("%e", 3.14); |
| %g / %G | Shortest of %e or %f | printf("%g", 3.14); |
| %a / %A | Hexadecimal floating point | printf("%a", 3.14); |
| %c | Character | printf("%c", 'A'); |
| %s | String | printf("%s", "Hello"); |
| %p | Pointer | printf("%p", ptr); |
| %n | Number of characters so far (writes to int*) | printf("%n", &x); |
| %% | Literal percent sign | printf("%%"); |