PHP Third Day

1, recursion: In the function of the body directly or indirectly call themselves.

The tedious and repetitive calling program in the refiner, and performs some more complex operation actions.

<?php

/**

* @author blog.anchen8.net

* @copyright 2014

*

*

* Declare a function named test for testing recursion

* $param int $n requires an integer as a parameter

*

*

*

*/

function test ($n) {//declares an argument named Test that has a parameter

echo $n. "         &nbsp;&nbsp; "; Outputs the function's value and two spaces at the beginning of a function

if ($n >0) {//Determine if the parameter is greater than 0

Test ($n-1); Call yourself if the parameter is greater than 0, and pass the parameter minus 1 again

} else {//Determine if the parameter is not greater than 0

echo "<-->"; Output delimited string

echo $n. "    &nbsp;&nbsp; "; Output parameter values and two spaces at the end of a function

}

echo $n. "    &nbsp;&nbsp; "; Output parameter values and two spaces at the end of a function

}

Test (10); Call the test function integer 10 to the parameter

?>

Results: 9 8 7 6 5 4 3 2 1 0 <-->0 1 2 3 4 5 6 7 8 9 10

Still don't understand .....