---
title: 1.17 Integer Format Specifiers
description: "Integer format specifiers control how integer values are represented by `printf()`. The length modifiers `h`, `l`, and `ll` specify the expected integer type. ``` #include int main() { int a = -25; unsigned int b = 25; long c =…"
url: "https://edcret.in/docs/c-programming/basic-refreshers/1-17-integer-format-specifiers/"
updated: "2026-09-06"
category: C Programming / Basic Refreshers
---

# 1.17 Integer Format Specifiers

Integer format specifiers control how integer values are represented by `printf()`. The length modifiers `h`, `l`, and `ll` specify the expected integer type.

```
#include <stdio.h>

int main()
{
    int a = -25;
    unsigned int b = 25;
    long c = 100000L;
    long long d = 1000000000LL;

    printf("Decimal       : %d\n", a);
    printf("Unsigned      : %u\n", b);
    printf("Octal         : %o\n", b);
    printf("Hexadecimal   : %x\n", b);
    printf("Long          : %ld\n", c);
    printf("Long long     : %lld\n", d);

    return 0;
}
```

### Example Output

```
Decimal       : -25
Unsigned      : 25
Octal         : 31
Hexadecimal   : 19
Long          : 100000
Long long     : 1000000000
```

### Explanation

The basic integer conversion specifiers are:

| Specifier | Expected type | Representation |
| --- | --- | --- |
| `%d` | `int` | Signed decimal |
| `%i` | `int` | Signed decimal |
| `%u` | `unsigned int` | Unsigned decimal |
| `%o` | `unsigned int` | Octal |
| `%x` | `unsigned int` | Lowercase hexadecimal |
| `%X` | `unsigned int` | Uppercase hexadecimal |

For example:

```
printf("%x\n", b);
```

prints the value of `b` in hexadecimal.

### Integer Length Modifiers

Length modifiers can be combined with conversion specifiers:

| Format | Expected type | Purpose |
| --- | --- | --- |
| `%hd` | `int` | `short` value |
| `%hu` | `unsigned int` | `unsigned short` value |
| `%ld` | `long int` | Signed long |
| `%lu` | `unsigned long int` | Unsigned long |
| `%lld` | `long long int` | Signed long long |
| `%llu` | `unsigned long long int` | Unsigned long long |
| `%lx` | `unsigned long int` | Unsigned long in hexadecimal |
| `%llx` | `unsigned long long int` | Unsigned long long in hexadecimal |

For `printf()`, integer types narrower than `int`, such as `short`, undergo integer promotion before being passed as arguments. Therefore `%hd` still corresponds to the promoted argument type expected by `printf`, with the `h` modifier controlling how the value is interpreted for output.

The format specifier must match the argument type expected by the conversion specification. A mismatch can result in undefined behavior.