abs, labs, llabs, imaxabs - cppreference.com

##### cppreference.com

##### Search

Create account

##### Namespaces

- Page
- Discussion

##### Variants

##### Views

- View
- Edit
- History

##### Actions

# abs, labs, llabs, imaxabs

From cppreference.com
< c‎ | numeric‎ | math

Defined in header `<stdlib.h>` |  |
int abs( int n ); |  |
long labs( long n ); |  |
long long llabs( long long n ); |  | (since C99)
Defined in header `<inttypes.h>` |  |
intmax_t imaxabs( intmax_t n ); |  | (since C99)

Computes the absolute value of an integer number. The behavior is undefined if the result cannot be represented by the return type.

### [edit] Parameters

n | - | integer value

### [edit] Return value

The absolute value of `n` (i.e. `|n|`), if it is representable.

### [edit] Notes

In 2's complement systems, the absolute value of the most-negative value is out of range, e.g. for 32-bit 2's complement type int, INT_MIN is -2147483648, but the would-be result 2147483648 is greater than INT_MAX, which is 2147483647.

### [edit] Example

Run this code

    #include <stdio.h>
    #include <stdlib.h>
    #include <limits.h>

    int main(void)
    {
        printf("abs(+3) = %d\n", abs(+3));
        printf("abs(-3) = %d\n", abs(-3));

    //  printf("%+d\n", abs(INT_MIN)); // undefined behavior on 2's complement systems
    }

Output:

    abs(+3) = 3
    abs(-3) = 3

### [edit] References

- C11 standard (ISO/IEC 9899:2011):

  - 7.8.2.1 The imaxabs function (p: 218)

  - 7.22.6.1 The abs, labs and llabs functions (p: 356)

- C99 standard (ISO/IEC 9899:1999):

  - 7.8.2.1 The imaxabs function (p: 199-200)

  - 7.20.6.1 The abs, labs and llabs functions (p: 320)

- C89/C90 standard (ISO/IEC 9899:1990):

  - 4.10.6.1 The abs function

  - 4.10.6.3 The labs function

### [edit] See also

fabsfabsffabsl (C99)(C99) | computes absolute value of a floating-point value (|x|) (function) [edit]
cabscabsfcabsl (C99)(C99)(C99) | computes the magnitude of a complex number (function) [edit]
C++ documentation for abs

Retrieved from "http://en.cppreference.com/mwiki/index.php?title=c/numeric/math/abs&oldid=78872"