Who knows PHP?

Morrus · Jul 22, 2018

I've been teaching myself PHP this last week so that I can write my own web apps (character builders and the like). It's coming along well, but I've run into a block. I'm hoping that one of the many clever people on EN World can help me!

So....

I have an array:

skill[1]
skill[2]
skill[3]
... all the way to skill[13]

In each slot, there is the name of a skill, such as running, or stealth, or computers, or herbalism, etc.

The problem is that some slots will be duplicated. For example, the user may have selected herbalism three items during the character creation process, so three of those 13 slots are "herbalism".

What I need is a list of skills, and the number of times they've been taken. So rather than:

1. running
2. herbalism
3. jumping
4. computers
5. running
6. running
7. chess
8. woodworking
9. dodging
10. dodging
11. computers
12. swords
13. bows

I need:

1. running 3
2. dodging 2
3. computers 2
4. herbalism 1
5. chess 1
6. woodworking 1
7. swords 1
8. bows 1
9. jumping 1

So I need some kind of function to take that first list and turn it into the second list.

I know there's an array_count_values function in PHP, and I can get it to split out those values on the screen, but I don't know how to "work" with those values to put them into some kind of new array I can use.

Anybody got any ideas? Does that even make sense?

Morrus · Jul 22, 2018

I suppose another way to ask the same question—

‪Is there an easy way to take the output of array_count_values and put that into another, new array which stores the values and their number of occurrences?‬

Mustrum_Ridcully · Jul 22, 2018

I am not familiar with PHP, unfortunately.
I am however familiar with programming in general. I can tell you that this is probably not how you want to implement the skills in the long run, since it will be error-prone and hard to work with in the long run.

Use Key Value pairs. I am not familiar with PHP, as mentioned, but a brief look here: http://php.net/manual/en/language.types.array.php
suggests that arrays are innately capable of working as such.

As key, you could use the skill name, and the value is the skill rating.

When the player selects a skill during character creation, you can check (with array_key_exists) if it already has that skill. If not, you just add the new skill with rating 1 (or whatever the base rating is for the first time picking a skill.)
When the map already contains the kjey, you can instead set the value to the new skill to the one before +1.

Pseudo Code (Again, I don't actually program PHP, my current work is mostly C++ and a tiny bit of Python) Except that I forget semicolons and use double quotes where single quotes would be typical or whatever.)

if (array_key_exists($selectedSkill, $skills) {
skills($selectedSkill)=skills($selectedSkill)+1
} else {
skills($selectedSkill)=1
}

If you just want to know which skill the players has at all, you can use array_keys.
If you wanted to know what the players Herbalism skill is, you could write skills("Herbalism");

(It could be that the above code could actually omit the whole checking if the key even exists and be condensed to
skills($selectedSkill)=skills($selectedSkill)+1
It could be that PHP by defaults treats keys in an array that have never been set as a 0. In C++, this almost certainly wouldn't work, because an uninitialized variable will likely hold some basically random value. But interpreted language like PHP, JavaScript, Perl and Pyhton are usually simpler)

In the longer run, you are probably better off creating some objects, instead of using just raw arrays and strings and numbers. But to go into that, you will need to dig a bit deeper into fundamental programming topics like algorithms and data structures (and deeper into PHP as well.)

Maelish · Jul 22, 2018

Hi Morrus. Can I recommend you take your question to https://www.phphelp.com? You'll find some friendly help there.

Morrus · Jul 22, 2018

I figured it out eventually! Took a few hours, but I got there.

Maelish · Jul 23, 2018

@Morrus Will you post a link to your completed tool?

I do PHP as well, this is a tool of mine. I'm sure you'll recognize this Fantasy Coin Calculator from an old Dragon Magazine article.

Which brings up a question of my own, have there been any newer articles like Coins in a Coffer? I wouldn't mind adding a new feature or two.

Janx · Jul 23, 2018

yeah, what Mustrum is talking about is Associative Arrays in PHP. Instead of an integer index, you can use a string:
$arrSkills["Herbalism"]++;

that little snippet would mean every time somebody picks herbalism, it increments by one. Later, you can output all the skills and their scores:

Code:

for($i=0;$i<len($arrSkills);$i++) 
{
  echo($arrSkills($i);
  echo("BRTAGGHERE"); //won't let me post html tag on the forum :)
}

Mustrum_Ridcully · Jul 24, 2018

Morrus said:
I figured it out eventually! Took a few hours, but I got there.

It's not so important on EN World, since it's likely not frequented by desperate PHP beginners, but anywhere else you post programming questions like this: If you find the answer yourself, be so kind to present the answer, or at least some valuable hint.

It's a common programmer fate: Searching the internet for a question, you find someone having exactly the same question, hope that someone replied... And the only reply you find is: "Figured it out myself. It works now!".

Maelish · Jul 24, 2018

Mustrum_Ridcully said:
If you find the answer yourself, be so kind to present the answer, or at least some valuable hint.

It's a common programmer fate: Searching the internet for a question, you find someone having exactly the same question, hope that someone replied... And the only reply you find is: "Figured it out myself. It works now!".

I'd like to second this! It's the most frustrating thing in the world to have finally found someone with your exact problem - but they didn't post a solution.

Too bad there aren't more programming related places to hang out for developers specific to tabletop gaming. I only know of one Discord channel and a tiny group on Facebook.

Morrus · Jul 24, 2018

The answer was simple: the count function already does exactly that, and gives me the array I needed. I didn’t realise it created the array rather than just spat out some numbers to read.