Question

First of all, I’ve got a result array from a db query that i’m spitting out into a html list via a foreach. Secondly I have got a multi-dimensional array with related data in. The relationship is defined in both data sources by “entry_id”.

I want to query the multi-dimensional array on each iteration of the foreach to check if there is a matching entry_id, and if so i want to pull the page title out to add into my html list.
The multi-dimensional array looks like this:

array(4) { 
    [0]=> array(2) { 
            ["entry_id"]=> string(1) "1" 
            ["title"]=> string(4) "Page Title 1" 
        } 
        [1]=> array(2) { 
            ["entry_id"]=> string(1) "2" 
            ["title"]=> string(5) "Page Title 2"
        }
        [2]=> array(2) { 
            ["entry_id"]=> string(1) "3" 
            ["title"]=> string(8) "Page Title 3" 
        } 
        [3]=> array(2) { 
            ["entry_id"]=> string(1) "4" 
            ["title"]=> string(5) "Page Title 4" } 
        }

So firstly, how would you query that multi-dimensional array and get the page title out that you need on that iteration, bearing in mind the sub-arrays have identical keys?

Secondly, what is the most efficient method of doing this, I should also mention that the array could get very large in theory.

Answer 1

Transform the array so that you have the structure

entry_id => title

i.e.

array(
    "1" => "Page Title 1",
    "2" => "Page Title 2"
)

Then getting the title is just accessing the array with the value of the entry_id.

If you can, build the array like this from the beginning, if not, you have to iterate over it and create this structure.