Using regex to search the key in an array and return the value - PHP

Question

Suppose there is an array

$data = array(
    "key1" => "value1",
    "key2" => "value2",
    "key3" => "value3"
);

And there is a string which may contain one of the keys in this array. And I want the value of this key in the array.

For example, the string is "**^%$key1^&*" which contains "key1". What I want to do is to return the value1.

This example maybe better for understanding:

$fruits = array(
    "apple" => "red",
    "avocado" => "green",
    "orange" => "orange"
);

When the input is "Gala apple" I want the output to be "red"

What I can think for now is using foreach.

$str = "Gala apple";

foreach($fruits as $k=>$v) {
    if(preg_match('/'.$k.'/i', $str))
        return $v;
}

This code works.

But... is there any method can avoid the loop?

Are alphanumerical characters the only ones you want to keep in the string? http://stackoverflow.com/questions/659025/how-to-remove-non-alphanumeric-characters — chris85, Jan 20 '17 at 15:10
@chris85 that was a bad example, I have updated the question and I just want the string to match the key in array. — Linda, Jan 20 '17 at 15:39

Aram Petrosyan · Answer 1 · 2017-01-20T15:50:07.617

0

Why not just use strpos ?

$data = array(
    "key1" => "value1",
    "key2" => "value2",
    "key3" => "value3",
);

$str = "!&!%key3!@#$$";
for($data as $key=>$value) {
    if (strpos($str, $key) !== false) {
        return $value;
    }
}

edited Jan 20 '17 at 15:50

answered Jan 20 '17 at 15:02

Aram Petrosyan

1
1
2

It is just general idea :) using strpos instead of regexp – Aram Petrosyan Jan 20 '17 at 15:07
@nerdlyist yes, "may contain" means if the key presented in the string, so **^%$key13^&* contains key1 whether you use regexp or strpos – Aram Petrosyan Jan 20 '17 at 15:25

score 0 · Answer 2 · edited May 23 '17 at 11:45

If the only alphanumerics chars in the key string are the valid key, you can strip the other chars using a function such as $result = preg_replace("/[^a-zA-Z0-9]+/", "", $s); from this SO post.

If you know the key, you can directly access the value using this syntax:
$array[$key]

Sample code:

$array = array(
    "key1" => "val1",
    "key2" => "val2",
    "key3" => "val3",
    "key4" => "val4",
    );
echo $array["key2"];

This will echo val2.

To verify if a key exists, you may use isset($array[$key]) or the array_key_exists($key, $array) method.

Using regex to search the key in an array and return the value - PHP

2 Answers2