abs(x) Description Calculates the absolute of two numbers. Syntax abs(x) Parameters x: the number Returns x: if x is greater than or equal to 0. -x: if x is less than 0. Notes and Warnings Because of the way the abs() function is implemented, avoid using other functions inside the brackets, it may lead to incorrect results. abs(a++); // avoid this - yields incorrect results abs(a); // use this instead - a++; // keep other math outside the function