PHP检查项目=值的JSON字符串

Question

I need to get the value one one particular value in my json string

the json string comes from an api url http://url:port/api.php?action=reg_user&sub=list and outputs like so

[{"id":"1","username":"username1","credits":"0","group_id":"1","group_name":"Administrators","last_login":"1511883014","date_registered":"1421604973","email":"test1@my-email.com","ip":"8.8.8.8","status":"1"},{"id":"31","username":"username2","credits":"0","group_id":"1","group_name":"Administrators","last_login":"1539813642","date_registered":"1473632400","email":"test2@my-email.com","ip":"8.8.8.8","status":"1"},

i would like to check the value of credits where username = username1

then if credits > 30 do x, else do y

I presume first of all I need to decode this jason string

so i tried to do

$api_result = file_get_contents( 'http://url:port/api.php?action=reg_user&sub=list' );
$json_decode = json_decode($api_result);
echo $json_decode;

expecting this to echo the array in a nicely formatted structure, instead it just outputs the word Array . Where do I go from here?

Thanks

UPDATE 1...

SO i checked again and I defo can echo $api_result so I know that the file_get_contents is working fine i tried the two comments suggestions however both didn't work...

one of the suggestions was to make my php $api_result = file_get_contents( ' http://url:port/api.php?action=reg_user&sub=list ' ); $json_decode = json_decode($api_result); echo $json_decode['username'];

here is a screenshot of how the echo $api_result is formatted in case this isnt a propper json string

so to me this looks like it opens with (and is all contained in a pair of [] and then each result is enclosed in {} as I'd expect with a json string right? however i thought json strings used {} and arrays used {} so to me this looks like a string inside an array???

I looked at php.net's resource on JSON DECODE and tried var_dump(json_decode($json)); which did print me this

UPDATE 2

I just tried https://www.functions-online.com/json_decode.html and pasted the data in, it was able to decode the data absolutely fine,

It then gave me a copy if the json_decode sample at the bottom but this didn't work either, returning a null value like json_decode doesn't work on my server?

Answer 1

From your second screenshot (please cut & paste the text instead!) you can see the decoded JSON is an array of objects with properties id , username etc. So you can access them using object notation. This code uses the snippet of your api_result from your original question to demonstrate how to do what you want:

$api_result = '[{"id":"1","username":"username1","credits":"0","group_id":"1","group_name":"Administrators","last_login":"1511883014","date_registered":"1421604973","email":"test1@my-email.com","ip":"8.8.8.8","status":"1"},{"id":"31","username":"username2","credits":"0","group_id":"1","group_name":"Administrators","last_login":"1539813642","date_registered":"1473632400","email":"test2@my-email.com","ip":"8.8.8.8","status":"1"}]';
$json = json_decode($api_result);
foreach ($json as $user) {
    if ($user->username == 'username1') {
        if ($user->credits > 30) {
            // do x
            echo "user $user->username has more than 30 credits ($user->credits)";
        }
        else {
             // do y
            echo "user $user->username has less than or equal to 30 credits ($user->credits)";
        }
    }
}

Output:

user username1 has less than or equal to 30 credits (0)