TutorialsPoint
tutorialspoint.com › c_standard_library › c_function_abs.htm
C library - abs() function
The C stdlib library abs() function is used to returns the absolute value of the specified number, where absolute represents the positive number. This function only returns the positive integer.
Cppreference
en.cppreference.com › w › c › numeric › math › abs.html
abs, labs, llabs, imaxabs - cppreference.com
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. ... #include <limits.h> #include <stdio.h> #include <stdlib.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 }
Videos
Absolute Value Function abs() | C Programming Tutorial - YouTube
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C Programming Tutorial - 37 - Absolute Value with abs - YouTube
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Programiz
programiz.com › cpp-programming › library-function › cmath › abs
C++ cmath abs() - C++ Standard Library
Become a certified C++ programmer. Try Programiz PRO! ... The abs() function in C++ returns the absolute value of the argument.
W3Schools
w3schools.com › c › ref_stdlib_abs.php
C stdlib abs() Function
C Examples C Real-Life Examples C Exercises C Quiz C Code Challenges C Compiler C Syllabus C Study Plan C Interview Q&A C Certificate ... The abs() function returns the absolute (positive) value of a number.
C For Dummies
c-for-dummies.com › blog
The abs() Function | C For Dummies Blog
November 12, 2016 - The point is that you find yourself needing positive values from time to time and the abs() function guarantees that result. For example, you subtract variable b from a, which returns the difference. The result could be positive or negative.
Linux Man Pages
man7.org › linux › man-pages › man3 › abs.3.html
abs(3) - Linux manual page
Returns the absolute value of the integer argument, of the appropriate integer type for the function.
Scaler
scaler.com › home › topics › abs() function in c
abs() Function in C - Scaler Topics
March 21, 2024 - In the C programming language, the use of the function abs in C is to return the absolute value of an integer. By integer, it means that the abs() is an arithmetics function.
Arduino
docs.arduino.cc › language-reference › en › functions › math › abs
abs()
April 25, 2025 - Arduino programming language can be divided in three main parts: functions, values (variables and constants), and structure.
Codecademy
codecademy.com › docs › c# › math functions › .abs()
C# (C Sharp) | Math Functions | .Abs() | Codecademy
November 19, 2025 - The C# Math.Abs() method is a static method that returns the absolute value of a specified number.
TechOnTheNet
techonthenet.com › c_language › standard_library_functions › stdlib_h › abs.php
C Language: abs function (Absolute Value of Integer)
In the C Programming Language, the abs function returns the absolute value of an integer.
Top answer 1 of 8
20
Since they are the implementation, they are free to make as many assumptions as they want. They know the format of the double and can play tricks with that instead.
Likely (as in almost not even a question), your double is the binary64 format. This means the sign has it's own bit, and an absolute value is merely clearing that bit. For example, as a specialization, a compiler implementer may do the following:
template <>
double abs<double>(const double x)
{
// breaks strict aliasing, but compiler writer knows this behavior for the platform
uint64_t i = reinterpret_cast<const std::uint64_t&>(x);
i &= 0x7FFFFFFFFFFFFFFFULL; // clear sign bit
return reinterpret_cast<const double&>(i);
}
This removes branching and may run faster.
2 of 8
11
There are well-known tricks for computing the absolute value of a two's complement signed number. If the number is negative, flip all the bits and add 1, that is, xor with -1 and subtract -1. If it is positive, do nothing, that is, xor with 0 and subtract 0.
int my_abs(int x)
{
int s = x >> 31;
return (x ^ s) - s;
}
The Open Group
pubs.opengroup.org › onlinepubs › 9799919799 › functions › abs.html
abs
[CX] The functionality described ... unintentional. This volume of POSIX.1-2024 defers to the ISO C standard. The abs() function shall compute the absolute value of its integer operand, i....
Code Browser
codebrowser.dev › glibc › glibc › stdlib › abs.c.html
abs.c source code [glibc/stdlib/abs.c] - Codebrowser
Source code of glibc/stdlib/abs.c glibc glibc-2 on KDAB Codebrowser
Cplusplus
cplusplus.com › reference › cstdlib › abs
abs
The absolute value of n. In C, only the int version exists. For the long int equivalent see labs.
Fresh2Refresh
fresh2refresh.com › home › c programming tutorial › c – arithmetic functions › c – abs() function
C abs() function | C Arithmetic functions | Fresh2Refresh
September 23, 2020 - C abs() function:abs( ) function in C returns the absolute value of an integer. The absolute value of a number is always positive.
Wikibooks
en.wikibooks.org › wiki › C_Programming › stdlib.h › abs
C Programming/stdlib.h/abs - Wikibooks, open books for an open world
Many programming languages have functions that calculate absolute values of numbers, either having the name abs or Abs. In languages such as C, it has variants for long integers and floating point numbers called labs and fabs.
Cprogramming.com
cprogramming.com › fod › abs.html
abs - C/C++ Function Reference - Cprogramming.com
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Draft C++ Standard
eel.is › c++draft › c.math.abs
[c.math.abs]
🔗constexpr floating-point-type abs(floating-point-type x);