Devil numbers in programs

The use of devil numbers (numbers without specific meanings, strings, etc.) in the Code will make the code difficult to understand, and the number should be defined as a meaningful constant of the name.

The ultimate goal of defining a number as a constant is to make the code easier to understand, so it is not a devil number to define a number as a constant. If the constant name is meaningless, it cannot help you understand the code. It is also a devil number.

In some cases, defining a number as a constant makes the code more difficult to understand. In this case, you should not forcibly define the number as a constant.

Case

// The Devil's number cannot be understood. 3. What is the status of the product?

If (product. getproduct (). getproductstatus ()! = 3)

{

Throw new pmsexception (pmserrorcode. Product. add_error );

}

// It is still the devil's number, and it cannot be understood what kind of status num_three represents.

If (product. getproduct (). getproductstatus ()! = Num_three)

{

Throw new pmsexception (pmserrorcode. Product. add_error );

}

// Although the number is defined as a constant in the example, the code is not easy to understand.

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;

// Directly use numbers to make the code 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;

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