在php中搜索foreach循环中的动态键值

Question

I feel like i'm missing something quite simple. What are some of the best ways to iterate through combinations of $key names -- doing something different for each-- in a php foreach loop?

I have a number of values in an array with key values that follow the same naming format.

Example:

$rec_items['title3'] = implode($meta['title3']);
$rec_items['title4'] = implode($meta['title4']);
$rec_items['title5'] = implode($meta['title5']);

The $rec_items array also contains other values that do not follow this naming convention (or data type).

I'm looping through $rec_items with a foreach loop. I would like to be able to dynamically cycle through key names in $rec_items, and 'do something' when a key is found that matches title*. I've tried pushing numeric numbers from a counter variable into key names to be searched for (like below):

foreach ($rec_items as $key => $value){
    $c = 0;
    if(!empty($key[${'title'.$c}]){
        $c++;
        //do something


}

I believe that I cannot pass the value ${'title'.$c} into $key[] and have tried to pass the value of ${'title'.$c} as a string with no luck.

I just share the above to try to highlight what i'm trying to achieve.

(1) dynamically loop through key names in the format 'title*'

(2) if the key name is present in the $rec_items array ... do something.

Answer 1

I'm not sure what your original code was trying for; you appeared to be treating the array key like an array itself? Using a variable variable? Anyway, you just need a simple string search of the key. You can use regular expressions or whatever you like for more complex matching.

<?php
$rec_items = ["foo"=>12, "bar"=>34, "title1"=>56, "title2"=>78, "baz"=>90];
foreach ($rec_items as $k=>$v) {
    if (strpos($k, "title") === 0) {
        echo "$k = $v
";
    }
}

Output:

title1 = 56
title2 = 78