extracting json in php - php

Question

From MySQL row, I have this json formatted data:
$row['details'] =
{
"previous_employer":[
{"employer":"string1","address":"address1"},
{"employer":"string2","address":"address2"},
{"employer":"string3","address":"address3"}],
"profile":[
"firstname":"John",
"lastname":"Adams",
"gender":"male",
"age":"35",
"contact":"123456789"]
}
I want to extract employer and address on the previous_employer array of objects,
but when I do this:
$json = json_decode($row['details'],true); //decode into array
foreach($json['previous_employer'] as $d){
echo "employer:".$d['employer']."<br>address:". $d['address']."<br>";
}
it gives me an error of
Warning: Invalid argument supplied for foreach()
How can I fix this? Pls advise.. thanks!

Answer 1

You JSON is invalid, "profile" must be
An Object:
"profile": {
"firstname": "John",
"lastname": "Adams",
"gender": "male",
"age": "35",
"contact": "123456789"
}
or an Array of Object (here his length == 1)
"profile": [{
"John",
"Adams",
"male",
"35",
"123456789"
}]
or a Simple Array (not associative array/map)
"profile": [
"John",
"Adams",
"male",
"35",
"123456789"
]
Now, your posted code will work as a charm without any modifications ... :)

Answer 2

json_decode() does not necessarily succeed (just imagine you feed it with complete garbage, why should it return something?). You need to do the following error checking:
Verify its return value:
Returns the value encoded in json in appropriate PHP type. Values
true, false and null are returned as TRUE, FALSE and NULL
respectively. NULL is returned if the json cannot be decoded or if the
encoded data is deeper than the recursion limit.
If valid data can be expected to return null some times, call json_last_error() and check whether it's JSON_ERROR_NONE.
Last but not least, you can explore any variable with var_dump(). You don't need to make assumptions about its content.