Talk about the sixth PHP bullet ---- use the for loop to output the 9-9 multiplication table

Last renewed!

These days I found that some children's shoes still have some problems in outputting the multiplication table. Today I will give you a detailed explanation...

First, let's look at the Code:
<? Php
For ($ I = 1; $ I <= 9; $ I ++ ){
For ($ j = 1; $ j <= $ I; $ j ++ ){
Echo "$ j x $ I =". $ j * $ I ."";
}
Echo "<br> ";
}
?>
Output result:

 

Well, let's further analyze:

We call the outermost loop a "Trip ":

First trip:

$ I is 1, meeting $ I <= 9,

While the inner loop $ j satisfies $ j <= $ I and outputs 1x1 = 1.

$ J auto-increment 1, no longer meet $ j <= $ I, no output

Output "<br/>" line feed,

$ I auto-increment 2

This trip ends.

Second trip:

If $ I is 2 and $ I <= 9 is met, the second loop is executed.

The condition of the inner loop becomes:

For ($ j = 1; $ j <= 2; $ j ++ ){
........
}

The inner layer loops output twice, respectively:

1x2 = 2 and 2x2 = 4

Similarly, when $ j in the inner loop is added to 3, the inner loop is no longer executed.

Output "<br> ";

$ I auto-increment is 3

This trip is over!

Third trip:

Same as above .....

And so on:

Until the Ninth:

$ I has been added as 9

$ I <= 9 is still valid

Execute the inner loop of the ninth round:

At this time, the inner loop changes

For ($ j = 1; $ j <= 9; $ j ++ ){
...........
}

The code in the loop body is executed cyclically 9 times,

Are

1x9 = 1 2x9 = 18 ...... 9 = 81

That is, the last line of the result.

At this time, $ j no longer meets $ j <= 9, and the execution of the inner loop ends.

Output "<br/>"

$ I auto-increment is 10

This trip ends.

By the time of the tenth round, $ I is 10 and no longer meets $ I <= 9. At this point, this Round Robin will not be executed.
The displayed 9-9 multiplication table is output.

I don't know if you understand it. If you understand it, try to output the 9-9 multiplication table in turn! The principle is the same!



Author: zdrjlamp