Computer Science Canada

traverse 2d array with foreach()
Author:  iker [ Thu Nov 19, 2009 1:15 am ]
Post subject:  traverse 2d array with foreach()
Hey, so i haven't been active on these forums in forever...

I'm having an issue with pulling the size of a 2d array

so heres the boring info if you wanto know what I'm doing

I'm working on a team project for one of my classes and our prof decided that we should do a blackberry web gps based game.. I was put on the php/javascript team (with no past php experience) and I'm having some troubles.
So I have an onClick() java function which enables up to 3 buttons(you click on character and it lets you pick from 3 weapons to attack with).. this is called from within some php code within a foreach() loop. The loop goes through each player and creates a div and draws their image in there.
There's a database call that returns a 2d array of the weapons that can fire at the enemy(if in range)..

so the 2D array has up to 3 weapons stored in [i][0]
their attack power stored int [i][1]
and range stored in [i][2]

and here's what really matters

what I need to do is pull the amount of weapons within the 2d array, or count the first dimension of the array - so that I can use this number like foreach(numberOfElementsInFirstDimension)
I'm thinking there might be a way like count all elements and divide by 3(because second dimension has 3 elements per first), but i've had no luck so far finding a solution

I'll upload some code tomorrow, for some reason I can't access my Uni's server from home..
feel free to give me any pointers for the mean time, and sry if someone already posted answer.. I don't even know what to search for[/b]
Author:  Tony [ Thu Nov 19, 2009 1:44 am ]
Post subject:  RE:traverse 2d array with foreach()
foreach doesn't work like that. You don't need the count -- see the docs: http://php.net/manual/en/control-structures.foreach.php
php:

/* foreach example 4: multi-dimensional arrays */
$a = array();
$a[0][0] = "a";
$a[0][1] = "b";
$a[1][0] = "y";
$a[1][1] = "z";

foreach ($a as $v1) {
    foreach ($v1 as $v2) {
        echo "$v2\n";
    }
}
Author:  iker [ Thu Nov 19, 2009 10:47 am ]
Post subject:  Re: traverse 2d array with foreach()
Hey, thanks for the quick reply

so if i had
php:

$a = array();
$a[0][0] = "name1";
$a[0][1] = "att1";
$a[0][2] = "ran1";
$a[1][0] = "name2";
$a[1][1] = "att2";
$a[1][2] = "ran2";
$a[2][0] = "name3";
$a[2][1] = "att3";
$a[2][2] = "ran3";

as my array thats returned by the database,
php:

foreach ($a as $v1) {
    foreach ($v1 as $v2) {
        echo "$v2\n";
    }
}

will echo every element.

how would I just pull the names(name1, name2, name3) out of the array without the attack and range?
Author:  Tony [ Thu Nov 19, 2009 12:16 pm ]
Post subject:  RE:traverse 2d array with foreach()
name, att, ran are elements of the array. If you don't want all of them, then don't loop over all of them.
Author:  iker [ Fri Nov 20, 2009 9:39 pm ]
Post subject:  Re: traverse 2d array with foreach()
k, fixed it. thank you tony

i'm using
php:

foreach ($a as $v) {
        echo "$v[0]\n";
}

and its echoing just the first element like I wanted

:


You can syndicate this boards posts using the file backend.php or view the topic map using sitemap.php.

Terms of Use | Privacy Policy