PHP Build a Basic PHP Website (2018) Listing and Sorting Inventory Items Random Fun with Arrays

Daniel Fitzhugh
Daniel Fitzhugh
9,470 Points
Posted by Daniel Fitzhugh
Daniel Fitzhugh
9,470 Points

Why does array_rand() return a "meta-array" of keys, and not just the original array with a reduced number of items ?

I noticed a recurring theme with the videos in this course regarding how to "filter" or "select a subset" from a master array. I've seen the same confusing technique in both of these videos:

https://teamtreehouse.com/library/random-fun-with-arrays https://teamtreehouse.com/library/sorting-multidimensional-arrays

The teacher always seems to create a "meta-array" of keys, and then juggles the parameters (in a really confusing way) to get the results that she wants.

Would it not be easier --- especially for this task, "Random fun with arrays" --- if array_rand() just produced an array which was similar in structure to the master array, which we could then iterate through using a "foreach" loop, without having to do all of the confusing parameter juggling that the teacher does whenever she uses her preferred technique ?

Sorry if this is confusing.... it confuses me also :)

Michael Cook
Michael Cook
Full Stack JavaScript Techdegree Student 22,559 Points
Michael Cook
Michael Cook
Full Stack JavaScript Techdegree Student 22,559 Points

"Sorry if this is confusing.... it confuses me also :)"

Yeah, it is confusing. I was confused too with a lot of these videos and I plan to go back and re-watch some of them, just for the satisfaction of really getting it. But ultimately, I think its just her way of doing it that's confusing and not the concept itself. I consistently use $key => $value when I am working with associative arrays, and the consistency helps prevent confusion, but at times she doesn't seem to be consistent.

Also, I really recommend reading the PHP docs often. At first I found them confusing but then I read an article explaining how to read the docs, and now I read them all the time. They really clarify things, which is what they're supposed to do.

Here are the docs for array_rand(): http://php.net/manual/en/function.array-rand.php

Basically, if you just want a single random item from an array, it will spit out one random $key that you can use to access the associated $value. If you want more than one random item in the array, it will return an array of random $keys. So let's say you have an array $myArray that has a count of int 10. You want 3 random $values. You could do $randomKeys = array_rand($myArray) and then iterate through $randomKeys with a foreach loop and do whatever you want with the random values from $myArray like this: 

$myArray = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

$randomKeys = array_rand($myArray, 3);

foreach ($randomKeys as $key) {
  echo $myArray[$key];
}

I hope this makes sense and I hope I actually helped clarify this for you :P. Not sure if this answer will help at all.