abs() in C++

Syntax of abs() in C++

The syntax of abs in C++ is:

Parameters of abs() in C++

The abs in C++ take only one parameter, but it can be of three data types:

1. int
2. long int
3. long long int

Return Values of abs() in C++

• The abs() in C++ return the absolute value of a number.
• The data type of returned value by abs in C++ will be equal to the data type of the argument passed, which means it could be int, long int, or long long int.

Example for abs() in C++

Output:

Explanation

• As we have discussed, abs() in C++, return the absolute value of the value passed. In the above code, for integer number num = -42, the absolute value of -42= |-42| = 42, so abs(-42) will return 42.
• For integer number num1 = 42, the absolute value of 42 = |42| = 42, so abs(42) will return 42.
• For integer number num2 = 0, the absolute value of 0 = |0| = 0, absolute value of 0 is 0, so abs(0) will return 0.

abs() Prototypes

There are the following three prototypes of abs in C++.

• If the num passed is of int type, then the return will be of int type.
• If the num passed is of long type, then the return will be of long type.
• If the num passed is of long long type, then the return will be of long long type.

Exceptions of abs() in C++

No-throw guarantee: this function throws no exceptions.

If the result cannot be represented by the returned type in an implementation with two's complement signed values, it causes undefined behavior.

For Example: abs is called on INT_MIN = -2147483648. The range of int in C++ is from -2147483648 to 2147483647. So if abs(-2147483648) is called, it will do (-1)*(-2147483648), which will result in it being out of range of int. Thus it will give undefined behavior.

What is cstdlib abs() in C++?

The abs() in C++ returns the absolute value of an integer number.

• If the number is negative, it will return the positive value (with the same magnitude), for example, abs(-1) = 1.
• If the number is already positive or zero, it will return the number as it is, for example, abs(1) = 1.

What is cstdlib fabs() in C++?

The fabs() in C++ returns the absolute value of a integer, float, or double-type value. In case of char type, it returns the ASCII code of that character.

• If the number is negative, it will return the positive value (with the same magnitude), for example, abs(-1) = 1.
• If the number is already positive or zero, it will return the number as it is, for example, abs(1) = 1.

Example: fabs() with char input

Code

Output

Difference Between abs() and fabs() in C++

The prototype of abs() in C++ is:

The prototype of fabs() in C++ is:

abs() Overloading

The abs() in C++ can be overloaded to be used for floating, complex types .

• cmath header file is to be included for floating-point types.
• complex header file is to be included for complex numbers.

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See Also:

• fabs().
• Header Files in C++.