Completing the React Function of a Common Browser Menu

We have another if-statement. The value of slicedStr is the slice from otherSpanNo. The condition of this if-statement tests to see if slicedStr is not equal to spanNo. If that test returns true, then we can go on to do the actual cleaning; that is, the statements in the if-block will be executed. These statements are the final statements in the code segment.

When slicedStr is not equal to spanNo, it means that the cell at the iteration has to be cleaned up. Cleaning up means you get the copy of the SPAN element from the Copy Table and place it in the corresponding cell, which is the cell at this iteration. The value of the display property of the copy is "none." So the copy is not seen in our table.

The first statement in the if-block forms the ID of our cell at the iteration. The second statement forms the ID of the corresponding cell at the Copy Table. The next statement makes a copy of the SPAN element from the Copy Table into our table. When no SPAN element is displayed in a cell of our table, the background color has to be transparent. The next statement makes the background color of the cell transparent. The last two statements give the value “” as content to the corresponding cells in the Boolean and Number Tables respectively.

All of this occurs n the seventh code segment, and everything in the react() function happens so fast that the user will not notice it.

Some of Your Worries

You may ask, “Why not change the value of the display property of a SPAN element using the SPAN’s ID and the getElementById() method?” This may work with one browser and not work with other browsers. We need an approach that will work with as many browsers as possible.

There are many questions like this that you may ask in this series. That answer is that we keep using an approach that works with as many browsers as possible. That is why the design is not straightforward.

We have finished with the details of the seventh code segment. The react function is the longest function in this series. We have to see the details of two more functions. These are short functions. We continue in the next part.