如何使用for循环按降序排列值

Question

I am showing a list of years in a dropdown box. The years range from 2017 to the current year. Currently, the values are shown in my dropdown starting from 2017 and increasing up to the current year. But I want the values to be shown in descending order, with the current year (2019) on top, then 2018, and finally 2017.

Here is my current code:

<?php
for ($i=2017; $i < date("Y")+1; $i++) { 
?>
  <option value="<?php echo$i?>" <?php if($_POST['master_year']== $i) {echo 'selected';} ?>><?= $i;?></option>
<?php 
}
?>

How can I change this to show them in descending order?

Answer 1

Simply change the order of your for loop. You initialize $i at 2017 to start. Then, you end it when it is equal to date("Y"). You add 1 to it each loop. Reverse all of that:

for($i = date('Y'); $i >= 2017; $i--)

This is not unique to PHP. This is the basic construct of a for loop. If you are having trouble with it, PLEASE do not develop anything critical. Take time to learn the basics of control structures in programming first.