In C language, abs is a mathematical function used to calculate absolute value. It returns the positive value of a given parameter, regardless of whether its original value is positive or negative. This function is usually used to ensure that the output result is positive.

For a simple example, if you want to find the absolute value of -8, you can use the abs function and express it with abs(-8), and the result is 8. If we use abs(8), the result returned by the function is still 8.

The realization principle of abs function is simple: if the passed parameter is positive, the parameter itself is returned; If the parameter is negative, its reciprocal is returned. This method can ensure that the return value is always positive under any circumstances. The source code of this function is as follows:

int abs(int x) {

return x & gt0 ? x:-x；

The above code adopts the ternary operator (? :), if x is greater than 0, X itself is returned; otherwise, -x is returned, which is the inverse of X..

Abs function is usually used in situations involving digital calculation, such as mathematical operation and data analysis. The following is an example of using abs function:

# Including

# Including

int num =-5；

int ABS _ num = ABS(num)；

Printf (the absolute value of "%d is %d.\n", num, ABS _ num);

Returns 0;

In the above code, we first define an integer variable num and assign it to -5. Then we use abs function to assign the absolute value of num to another integer variable abs_num. Finally, we use printf function to output the values of num and abs_num.