php- why traversing multidimensional array inside the foreach() doesnt work

Question

I"m trying to traverse on an object i"m getting from openweather.com

without the foreach() i"m getting the right result. inside the foreach() i get an error.

the php code:

 $contents = file_get_contents($url); 
 $clima=json_decode($contents,TRUE);

 echo $clima['list'][5]['main']['temp'];  // this one works

 $i=0;
 foreach($clima['list'] as $clima1) {
     echo $clima1[$i]['dt'];   // here i get PHP Notice:  Undefined offset

     echo $clima1[$i]['main']['temp']; //here i get PHP Notice:  Undefined index: list

     $i=$i+1;
 }

the error that i get is:

PHP Notice:  Undefined offset: 0   // the error is from 0 to 39 and there are 39 objects...
PHP Notice:  Undefined index: list

the object beginning and ending part for sample:

Array ( [cod] => 200 [message] => 0.014 [cnt] => 40 [list] => 
Array ( [0] => Array ( [dt] => 1492732800 [main] => Array ( [temp] => 17.64 [temp_min] => 17.04 [temp_max] => 17.64 [pressure] => 1026.03 [sea_level] => 1031.21 [grnd_level] => 1026.03 [humidity] => 100 [temp_kf] => 0.6 ) [weather] => Array ( [0] => Array ( [id] => 800 [main] => Clear [description] => clear sky [icon] => 01n ) ) [clouds] => Array ( [all] => 0 ) [wind] => Array ( [speed] => 1.66 [deg] => 81.5008 ) [sys] => Array ( [pod] => n ) [dt_txt] => 2017-04-21 00:00:00 ) 
        [38] => Array ( [dt] => 1493143200 [main] => Array ( [temp] => 19.72 [temp_min] => 19.72 [temp_max] => 19.72 [pressure] => 1026.92 [sea_level] => 1032.02 [grnd_level] => 1026.92 [humidity] => 87 [temp_kf] => 0 ) [weather] => Array ( [0] => Array ( [id] => 800 [main] => Clear [description] => clear sky [icon] => 01n ) ) [clouds] => Array ( [all] => 0 ) [wind] => Array ( [speed] => 6.95 [deg] => 10.5008 ) [sys] => Array ( [pod] => n ) [dt_txt] => 2017-04-25 18:00:00 ) 
         [39] => Array ( [dt] => 1493154000 [main] => Array ( [temp] => 18.43 [temp_min] => 18.43 [temp_max] => 18.43 [pressure] => 1026.75 [sea_level] => 1031.91 [grnd_level] => 1026.75 [humidity] => 98 [temp_kf] => 0 ) [weather] => Array ( [0] => Array ( [id] => 800 [main] => Clear [description] => clear sky [icon] => 01n ) ) [clouds] => Array ( [all] => 0 ) [wind] => Array ( [speed] => 6.03 [deg] => 9.50076 ) [sys] => Array ( [pod] => n ) [dt_txt] => 2017-04-25 21:00:00 ) ) 
 [city] => Array ( [id] => **** [name] => ***** [coord] => Array ( [lat] => **.**** [lon] => **.**** ) [country] => ** ) )

any help to understand my mistake will be appreciated

$clima1['dt'] and $clima1['main']['temp']. Why did you even add $i there? — zerkms
– zerkms, Commented Apr 20, 2017 at 22:45
i misunderstood the output of var_dump. i removed the [$1] and now it's ok. thanks, all 3 answers helped me understand my mistake — ic205
– ic205, Commented Apr 21, 2017 at 12:03

Philipp · Accepted Answer · 2017-04-20 22:52:42Z

1

It seems, you loop "double". The counter inside the loop is the part, which you don't need, as you already loop over the array with foreach.

I think, the following code would be the better approach

 $contents = file_get_contents($url); 
 $clima=json_decode($contents,TRUE);

 echo $clima['list'][5]['main']['temp'];  // this one works

 foreach($clima['list'] as $clima1) {
     echo $clima1['dt'];   // here i get PHP Notice:  Undefined offset

     echo $clima1['main']['temp']; //here i get PHP Notice:  Undefined index: list
 }

answered Apr 20, 2017 at 22:52

Philipp

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Alex · Accepted Answer · 2017-04-20 22:48:53Z

1

That is because when you foreach over $clima['list'] you will get every values inside $clima['list']. Therefore, first, $clima1 = $clima['list'][0]. After that, $clima1 = $clima['list'][1]... Thus, $clima1 has neither 0 as an index nor 1 nor 2...

What you might do to see it more clearly is this :

foreach($clima['list'] as $key => $clima1)

And everytime, the $key will be your $id. Therefore, you can get rid of your $id and just do it like this :

foreach($clima['list'] as $id => $clima1)

answered Apr 20, 2017 at 22:48

Alex

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100pic · Accepted Answer · 2017-04-20 22:49:27Z

1

When you run foreach($clima['list'] as $clima1) { ... each object in the loop ($clima1) is equal to $clima['list'][$i] so you don't need to manually put the $i in there.

If your really stuck I'd just run the loop like:

foreach($clima['list'] as $clima1) {
    var_dump('<pre>' . $clima1 . '</pre>');
}

To see what the $clima1 variable really is.

answered Apr 20, 2017 at 22:49

100pic

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