Demon numbers in the program

Using the Devil Numbers in your code (numbers, strings, etc. that don't have a detailed meaning) will cause your code to be difficult to understand and you should define a number as a constant with a meaningful name.

The last goal of defining a number as a constant is to make the code easier to understand, so it's not just the Devil's number to define a number as a constant. Assuming that the name of a constant is meaningless and does not help to understand the code, the same is a demon number.

In some cases, defining a number as a constant will cause the code to be more difficult to understand, and it should not be forced to define a number as a constant.

Case

Devil number, can't understand. 3 What is the status of the product in detail?

if (Product.getproduct (). Getproductstatus ()! = 3)

{

throw new Pmsexception (PMSErrorCode.Product.ADD_ERROR);

}

is still the devil number, unable to understand what the status of Num_three in detail represents the product

if (Product.getproduct (). Getproductstatus ()! = Num_three)

{

throw new Pmsexception (PMSErrorCode.Product.ADD_ERROR);

}

In the example, the code is not easy to understand, although the number is defined as a constant

Point drawcenter = new Point ();

Drawcenter.x = parentwindow.x + (parentwindow.width-clientwindow.width)/half_size_div;

Drawcenter.y = Parentwindow.y + (parentwindow.height-clientwindow.height)/half_size_div;

return drawcenter;

Using numbers directly, the code is easier to understand

Point drawcenter = new Point ();

Drawcenter.x = parentwindow.x + (parentwindow.width-clientwindow.width)/2;

Drawcenter.y = Parentwindow.y + (parentwindow.height-clientwindow.height)/2;

return drawcenter;

Demon numbers in the program