abs, labs, llabs, imaxabs

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< c‎ | numeric‎ | math
 
 
 
Common mathematical functions
Functions
Basic operations
abslabsllabsimaxabs
(C99)
(C99)
(C99)
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(C99)
(C99)
(C99)(C99)(C99)
Exponential functions
(C99)
(C99)
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(C99)
Power functions
(C99)
(C99)
Trigonometric and hyperbolic functions
(C99)
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(C99)
Error and gamma functions
(C99)
(C99)
(C99)
(C99)
Nearest integer floating point operations
(C99)(C99)(C99)
(C99)
(C99)
(C99)(C99)(C99)
Floating point manipulation functions
(C99)(C99)
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Classification
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Macro constants
 
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.

Contents

[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

#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] See also

(C99)(C99)
computes absolute value of a floating-point value (|x|)
(function)
(C99)(C99)(C99)
computes the magnitude of a complex number
(function)