PHP preg_replace（）大写和小写区别

Question

I have a PHP/Ajax search function that returns all countries which hold the characters entered in a textbox. All these countries are listed and the given characters are marked bold inside the country it's name in the list.

Example Characters given in textbox: "Af" Which return Af ghanistan and South Af rica - without the space inbetween ofcourse

Now all the countries names in the database ofcourse start with a uppercase letter. But

preg_replace()

can not find the difference between Upper and lowercase letters. So when i enter "a" in the textbox it will return Afgh a nist a n notice the first uppercase "A" not made bold

Here is the code i am using

$display_name = preg_replace("/" . $search_string . "/", "<b>" . $search_string . "</b>", $result['Country_Name']);
$display_url = '';

$output = str_replace('NameReplace', $display_name, $HTML);
$output = str_replace('UrlReplace', $display_url, $output);
echo($output);

I can "fix" this problem adding the "/i" modifier to the preg_replace() According to PHP.net it will do the following:

i (PCRE_CASELESS) If this modifier is set, letters in the pattern match both upper and lower case letters.

This will turn the bold characters inside the countries name lowercase or uppercase according to the characters inside the textbox

example: Characters given in textbox: "A" will return " A fgh A nist A n" while "a" will return " a fgh a nist a n" again please ignore the white space.

How can i make it that when i enter: "a" it will return " A fgh a nist a n" ?

Thank you

Answer 1

Change this:

$display_name = preg_replace("/" . $search_string . "/", "<b>" . $search_string . "</b>", $result['Country_Name']);

to this:

$display_name = preg_replace("/(" . $search_string . ")/i", '<b>$1</b>', $result['Country_Name']);

Answer 2

Try this:

echo preg_replace("/a/i", "<b>\1</b>", "Afghanistan");

Outputs in HTML :

A fgh a nist a n