PHP - Parsing nested JSON array values - php

Question

I have hit a wall and I am not sure what is causing this. I am parsing a JSON file and creating variables. All the ones that are not nested in arrays work great. These two below are not though and I am not sure why. $hail var value shows for both the hail and the $wind var and I am completely puzzled as to why.
Here is a snippet of the code to create the variable from the value.
$hail = isset($currFeature['properties']['parameters']['hailSize'][0]);
$wind = isset($currFeature['properties']['parameters']['windGust'][0]);
Here is how it is outputted and displayed in the HTML which it displays but shows $hail for both var.
<div class="alerts-description"> HAZARDS<br /><? if (isset($hail)) {echo $hail . '" Hail';} ?><br /> <? if (isset($wind)) {echo $wind . '" MPH Winds';} ?></div>
Example of array as both hailSize and windGust is nested under parameters and both [0]
[response] => Avoid
[parameters] => Array
(
[hailSize] => Array
(
[0] => 0.50
)
[windGust] => Array
(
[0] => 70
)
[VTEC] => Array
(
[0] => /O.NEW.KFWD.FA.W.0008.170813T1318Z-170813T1615Z/
)
[EAS-ORG] => Array
(
[0] => WXR
)
Any suggestions what I am doing wrong or am missing?
EDIT: Link to example code just hit the "Run it" button"
http://rextester.com/EELE62798
-Thanks!

Answer 1

$hail = isset($currFeature['properties']['parameters']['hailSize'][0]);
The above code will generate a variable with the value true or false. It will never have the value from your data.
The following PHP7 code is a possible solution.
<?php
$json = '{"properties":{"parameters":{"hailSize":[0.50],"windGust":[70]}}}';
$currFeature = json_decode($json, true);
$hail = $currFeature['properties']['parameters']['hailSize'][0] ?? null;
$wind = $currFeature['properties']['parameters']['windGust'][0] ?? null;
// check specifically for null
if ( $hail !== null ) {
echo $hail . '" Hail'. PHP_EOL;
}
// check specifically for null
if ( $wind !== null ) {
echo $wind . '" MPH Winds'. PHP_EOL;
}
if ( empty($currFeature['properties']['parameters']['windGust'][1]) ) {
echo "empty also works to check for missing data\n";
}
if ( ! isset($currFeature['properties']['parameters']['windGust'][1]) ) {
echo "isset to check for missing data\n";
}
If you run it on the command line you will get the following output:
0.5" Hail
70" MPH Winds
empty also works to check for missing data
isset to check for missing data