Adding two array values from different arrays

unlucky17

Double Edit: I was right... it's not working. See post below.

Bjom

works for me, right when I paste it, but you got to enclose the array keys in '' like this:

<?php 

$p1_stat = array(); 
$p1_stat['pts'] = 4; 

$p2_stat = array(); 
$p2_stat['pts'] = 3; 

$total = $p1_stat['pts'] + $p2_stat['pts']; 
echo $total; 

?>

read the array dos and don'ts in the php manual

unlucky17

OK, I should mention HOW this is not working rather than post a quick example. Turns out the problem isn't where I add the values together.. that works fine, it's a matter of a function updating the global variable, which it doesn't seem to do.

So, here's what I've got:

<?php

$p1_stat = array();
$p1_stat['pts'] = 0;

$p2_stat = array();
$p2_stat['pts'] = 0;

$t1_stat['pts'] = $p1_stat['pts'] + $p2_stat['pts'];

class sim
{
function add_values()
  {
  global $p1_stat;
  global $p2_stat;
  global $t1_stat;
  $p1_stat['pts']++;
  $p2_stat['pts']++;
  echo $t1_stat['pts'];
  }
}

$test = new sim;
$test->add_values();

?>

I'm hoping that if I update the array values via another function they should stick, then add together. It's like it will update the global array value properly to make p1 and p2's points 1 each, but it won't then follow through and update it with the t1 pts, keeping it at 0. So, either this code isn't adding 1 to the global array values, or the equation later on isn't considering p1_stat['pts'] (or p2 for that matter) to equal 1, but rather equal their original value of 0.

Hoo boy this is turning out to be a mess.

unlucky17

Hmm, well I think I have it working. Seems it's a little more complex than I thought. It works correctly if you add a function to update the t1_stat[pts] with the new values:

function add_totals()
  {
  global $p1_stat;
  global $p2_stat;
  global $t1_stat;
  $t1_stat['pts'] = $p1_stat['pts'] + $p2_stat['pts'];
  }

Then you call it from the class, making this the final code:

<?php

$p1_stat = array();
$p1_stat['pts'] = 0;

$p2_stat = array();
$p2_stat['pts'] = 0;

$t1_stat['pts'] = $p1_stat['pts'] + $p2_stat['pts'];

class sim
{
function add_values()
  {
  global $p1_stat;
  global $p2_stat;
  global $t1_stat;
  $p1_stat['pts']++;
  $p2_stat['pts']++;
  $this->add_totals();
  echo $t1_stat['pts'];
  }

function add_totals()
  {
  global $p1_stat;
  global $p2_stat;
  global $t1_stat;
  $t1_stat['pts'] = $p1_stat['pts'] + $p2_stat['pts'];
  }

}

$test = new sim;
$test->add_values();

echo $t1_stat['pts'];  // It will even put out the correct number if you call it outside of the object above.  So, it seems to work this way.

?>

Which is weird. I really would have thought if I added those other two values before I called back to get the total, it would have added them first and then gone back to execute the rest of the code in the first function. Kind of cumbersome, but... whatever.

Weedpacket

Perfectly reasonable if you look at your earlier code.

$p1_stat = array();
$p1_stat['pts'] = 0;

$p2_stat = array();
$p2_stat['pts'] = 0;

$t1_stat['pts'] = $p1_stat['pts'] + $p2_stat['pts'];

class sim
{
function add_values()
  {
  global $p1_stat;
  global $p2_stat;
  global $t1_stat;
  $p1_stat['pts']++;
  $p2_stat['pts']++;
  echo $t1_stat['pts'];
  }
}

$test = new sim;
$test->add_values();

Create an array called $p1_stat
Set its "pts" element to 0.
Create an array called $p2_stat
Set its "pts" element to 0.
Create an array called $t1_stat and set its "pts" element to the sum of $p1_stat['pts'] and $p2_stat['pts'] (since those are both 0, their sum is also 0).
Create a new sim object called $test.
Call $test's "add_values" method, which
1. Adds one to $p1_stat['pts']
2. Adds one to $p2_stat['pts']
3. Outputs the value of $t1_stat['pts'].

Why should $t1_stat['pts'] ever be anything other than 0? If you think PHP should have "gone back" to the addition and done it again because $t1_stat['pts'] was supposed to be equal to the result of adding $p1_stat['pts'] and $p2_stat['pts'] there would be nothing to stop it "going back" further and remembering that $p1_stat['pts'] and $p2_stat['pts'] were supposed to be equal to zero. And $t1_stat['pts'] would still be 0.

Incidentally, whatever it is you're doing, mixing up objects and global variables like this is almost certainly not the way to do it.

unlucky17

It makes sense once I sit back and think about it, but it's kind of weird that if you add 1 to both of the array values, and then you can immediately call those same array values and it will display the proper amount. But then if you call something that's supposed to add those together, it's like it doesn't care that you just updated the two values, it still stores the amounts of the older values at zero until you force it to look again. If there was some way to ask it to run that addition based on the newest updates to the code, that'd be great. But in learning that I need another function to do that, I can actually update a whole bunch of different things in that one function and then return or echo whatever it is I need... thus, saving me even more work. It's pretty cool when a mistake that would require a work-around results in something that will actually SAVE time later on rather than require more.

And basically what I'm doing is I'm making something similar to a sports simulation based on a ton of different factors, random number generators and accuracy to real life. While building I'm simply going through ways to optimize the code and make it easier to go back and modify it if need be. It's something I'm really doing as an experiment - I'm not getting paid, nor is it going to be implemented anywhere as far as I can tell. I'm just seeing what kind of situations can come up when you're coding and how to get around them while optimizing it as much as possible.

With the layout that I'm using there's a TON of array values that will need to be updated and called over and over and over by several different methods and classes (in total I'd estimate there's about 20 arrays, each with anywhere from 10 to 30 elements each.. you'd be surprised how many unique stats you have to keep for one silly sports game). The alternative to the way I'm setting it up would be to have one page house all of the code, or classes constantly calling one another and making additional functions to update each classes' variables (since you couldn't update a variable from one class from another class' method), and I assure you it'd be like 3000 lines of code once it's all done. I want to make separate files to each do their specific job while calling back and forth to one another as needed without making one giant file (and updating that giant file would be a pain because I'd have to scan through all of the code a million times and make sure everything was correct).

Anyway - just trying to gain some experience. It's nice that I have something like this forum to fall back on when I get into a state of confusion because of the complexity of the code. No better way to learn than by experience, right?

Thanks.

Bjom

Get rid of globals. It's as easy as that.

I have yet to be convinced that is ever necessary to declare anything global. Usually it is simply a way of evading the process of a proper application design.

I have used the equivalent of globals when I started coding in VBA - but I found out after a while...it sucks 😉. The sooner you get used to not using them the better.

Bjom