abs(), labs(), llabs() functions in C/C++

abs(), labs(), llabs() functions are defined in cstdlib header file. These functions return the absolute value of integer that is input to them as their argument.

1. abs() function: Input to this function is value of type int in C and value of type int, long int or long long int in C++. In C output is of int type and in C++ the output has same data type as input.
   Below is the sample C++ program to show working of abs() function.

   // CPP program to illustrate
   // abs() function
   #include <cstdlib>
   #include <iostream>
   
   using namespace std;
   
   int main()
   {
       int val1, val2;
   
       /// finding absolute value using
       /// abs() function.
       val1 = abs(22);
       val2 = abs(-43);
   
       cout << "abs(22) = " << val1 << "\n";
       cout << "abs(-43) = " << val2 << "\n";
       return 0;
   }

   Output: 
   abs(22) = 22
   abs(-43) = 43
   

2. labs() function: This is the long int version of abs() function. Both the input and output are of long int type.
   Below is the sample C++ program to show working of labs() function.

   // CPP program to illustrate
   // labs() function
   #include <cstdlib>
   #include <iostream>
   
   using namespace std;
   
   int main()
   {
       int val1, val2;
   
       /// finding absolute value using
       /// labs() function.
       val1 = labs(1234355L);
       val2 = labs(-4325600L);
   
       cout << "labs(1234355L) = " << val1 << "\n";
       cout << "labs(-4325600L) = " << val2 << "\n";
       return 0;
   }

   Output: 
   labs(1234355L) = 1234355
   labs(-4325600L) = 4325600
   

3. llabs() function: This is the long long int version of abs() function. Both the input and output are of long long int type.
   Below is the sample C++ program to show working of llabs() function.

   // CPP program to illustrate
   // llabs() function
   #include <cstdlib>
   #include <iostream>
   
   using namespace std;
   
   int main()
   {
       int val1, val2;
   
       /// finding absolute value using
       /// labs() function.
       val1 = llabs(1234863551LL);
       val2 = llabs(-432592160LL);
   
       cout << "llabs(1234863551LL) = " << val1 << "\n";
       cout << "llabs(-432592160LL) = " << val2 << "\n";
       return 0;
   }

   Output: 
   llabs(1234863551LL) = 1234863551
   llabs(-432592160LL) = 432592160