如何在php循环中检测a-z字母？ [关闭]

Question

I want to detect starting letter of string A-Z

Currently I am displaying data using loop which displays data from a to z

Now I want to detect data starting with letter "a" in loop

Is that possible using PHP?

I want same this http://cdn.ihwy.net/ihwy-com/labs/demos/jquery-listnav.html using PHP

Actually I want to add "Clear" name class after printing "a" letter data and so on for every letter (b,c,d.....z)

Answer 1

This should work if all of the categories are stored in an array

//Define the first letter that you want to focus on
$letter = 'b';

//Store all items in an array
$categories = array('Books', 'Marketing', 'TV', 'Radio', 'Computers');

//Loop thru
for($i=0;$i<count($categories);$i++)
{
    //This might be case sensitive, so lower the items and get the first letter of it
    if(strtolower(substr($categories[$i], 0, 1)) == $letter)
    {
         echo $categories[$i].'<br />';
    }
}

OR, if you're storing all of them in MySQL

//Connect to MySQL
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
//Query the DB for all categories beginnng with a particular letter
$query = "SELECT * FROM table WHERE category LIKE '".$letter."%'";
$result = mysqli_query($link, $query);
$count = mysqli_num_rows($result);
$i = 0;

while ($row = mysqli_fetch_assoc($result)) {
  $categories[$i] = $row['category'];

  $i++;
}

//Loop thru
for($i=0;$i<$count;$i++)
{
   echo $categories[$i].'<br />';
}

You produce the exact same effect that's shown on the link you provided, you'll need more than just PHP; you'll need JS too. But, that's another task.