Getting value from string by index - php

I have a string of data formatted like so:
[{"pr_a_w":"10","pr_a_we":"10","pr_c_w":"10","pr_c_we":"10"},{"pr_a_w":"20","pr_a_we":"20","pr_c_w":"20","pr_c_we":"20"},{"pr_a_w":"111","pr_a_we":"11","pr_c_w":"111","pr_c_we":"111"}]
The string doesn't have any index/numbers like a regular array would and I'm finding it difficult to extract individual values e.g. with a regular array I could use:
$string[0]["pr_a_w"]
To get the first instance of "pr_a_w" and I could use:
$string[1]["pr_a_w"]
To get the second instance etc.
Is it possible to get single values from this string based on their number?

What you have there is valid JSON (serialized array of objects), so you could use json_decode to translate the serialized data into a native PHP array:
$array = json_decode('[{"pr_a_w":"10","pr_a_we":"10","pr_c_w":"10","pr_c_we":"10"},{"pr_a_w":"20","pr_a_we":"20","pr_c_w":"20","pr_c_we":"20"},{"pr_a_w":"111","pr_a_we":"11","pr_c_w":"111","pr_c_we":"111"}]',true);
$array will then allow you to do exactly what you stated you'd like to do above.
$array[0]["pr_a_w"]; // will give you 10
$array[1]["pr_a_w"]; // will give you 10

Try like this, No need to access with array index. You will get error if you access wrong index.
$json_arr= json_decode('[{"pr_a_w":"10","pr_a_we":"10","pr_c_w":"10","pr_c_we":"10"},{"pr_a_w":"20","pr_a_we":"20","pr_c_w":"20","pr_c_we":"20"},{"pr_a_w":"111","pr_a_we":"11","pr_c_w":"111","pr_c_we":"111"}]',true);
foreach($json_arr as $row){
echo $row['pr_a_w']."<br>";
}

Related

interpreting JSON with PHP and putting it in array

I have only worked with JSON once before, but I don't recall how to use it with PHP.
If I have a script that returns JSON like this:
{
"bunisess":[
"business",
"bonuses",
"burnooses",
"boniness",
"burnoose's"
]
}
how can I take that and make each value a value in a PHP array. The keys just being numbers from 0 onwards?
Use json_decode, but pass true as the second parameter to get an associative array back:
$json='{"bunisess":["business","bonuses","burnooses","boniness","burnoose\'s"]}';
$data=json_decode($json, true);
Now, you can use array_values to get a numerically indexed array as you required:
$data=array_values($data);
A simple google search could have lead you to this page : http://php.net/manual/fr/function.json-decode.php
The subarray will be respecting exatcly what you're asking for.
Assuming that $data is the complete JSON string
$stdObject = json_decode($data, true);
print_r($array);
You should get an array with one key bunisess and value another numeric array with the other values.

PHP string to array keys

I have a string that holds the property and key values to accessing a value on an object..
For Example, the string is "property_name[key1][key2][key3]", which relates to $obj->property_name[key1][key2][key3]
I've been trying to parse the string with a regular expression, but all of my attempts have ben in vain.
So far, my regular expression looks like this, but it won't get key2.
^(\w+)\[([^\]]+)\](?:(\[([^\]]+)\])+)
Am I on the right track or is there a better way to do this that I should try?
Thanks.
The regular expression could look like this:
^(\w+)(?:\[(\w+)\])+
Then your matches will contain the property name and the array keys. If the number of keys varies, use this to get the actual value: Using a path to an array item
You should use AJAX instead and send a useful array with objects inside to the server that you can parse with PHP.
var changed_values = [
{
'part_of_form': 'XX',
'field': 2,
'subfield': 3
},
.......
]
Then in PHP you can loop over it:
foreach($_POST['changed_values'] as $changed_value) {
........
}

PHP multidimensional array to JSON

So im trying to figure out the best way to get MySql table data into either a multidimensional PHP array or convert that multidimensional array into a json string.
Essentially what im trying to do is have a php include that returns the JSON string so i can iterate through it. I am needing a single key with multiple values, so im not 100% sure that im headed in the right direction.
I want to assign multiple values to the same key, for example:
[{"key1": "package1", "package2", "package3"}, {"key2": "package1", "package2", "package3", "package4"}]
I think that is not going to work right? Because i dont have any type of index's?
That is not valid JSON. The structure you are looking for would be something like:
[
{"key1": ["package1", "package2", "package3"]},
{"key2": ["package1", "package2", "package3", "package4"}]
^ An array as the value to the key "key1", "key2", etc..
]
At the PHP side, you would need something like:
For every row fetched from MySQL
$arr[$key] = <new array>
for each package:
append package to $arr[$key]
echo out json_encode($arr)
JS arrays have an implicit array keying, starting at index 0. What you've got is a perfectly valid JS array, the equivalent of having written:
var x = []; // create new empty array
x[0] = {"key1": .... }; // first object
x[1] = {"key2": ....} // second object
Note that the contents of your {} sub-objects is NOT valid.
You should never EVER built a JSON string by hand. It's too unreliable and easy to mess up. It's just easier to use a native data structure (php arrays/objects), then json_encode() them. Ditto on the other end of the process - don't decode the string manually. Convert to a native data structure (e.g. json_decode(), JSON.parse()) and then deal with the native structure directly.
essentially, JSON is a transmission format, not a manipulation format.

build SQL statement from json encoded string php

Welcome Stackoverflow nation ! I'm trying to decode json encoded string into SQL statement withing php.
Lets say I've such a json encoded string =>
$j = '{"groupOp":"AND","rules":[{"field":"id","op":"cn","data":"A"},{"field":"i_name","op":"cn","data":"B"}]}';
I want to build SQL WHERE clause (needed for filterToolbar search in jqGrid), something like this => "WHERE id LIKE %A% AND i_name LIKE %B% " and etc.
I've done this =>
$d = json_decode($j);
$filterArray = get_object_vars($d); // makes array
foreach($filterArray as $m_arr_name => $m_arr_key){
// here I can't made up my mind how to continue build SQL statement which I've mentioned above
}
Any ideas how to do that , thanks preliminarily :)
The first problem is you will want to pull out the groupOp operator.
Then, you have an object and inside that you have an array of objects, so you may want to look at the results of filterArray as that won't have the value you want.
Then, when you loop through, you will want to do it with an index so you can just pull the values out in order.
You may want to look at this question to see how you can get data out of the array:
json decode in php
And here is another question that may be helpful for you:
How to decode a JSON String with several objects in PHP?
There is an answer with an implementation for the server-side php code here
Correction: I had to unescape double-quotes in the 'filters' parameter to get it working:
$filters = str_replace('\"','"' ,$_POST['filters']);

PHP text-extraction from string

I have the following string: a:2:{s:4:"user";b:1;s:6:"userid";s:2:"48";}
What I need to do is extract number 48 from it, in this case. This number could have any number of digits. How would I go about doing this?
It looks like you are facing a serialized strings. So, instead of trying to get that number using regular expression or any other string manipulation methods, try this:
$myVar = unserialize('a:2:{s:4:"user";b:1;s:6:"userid";s:2:"48";}');
$myNumber = $myVar['userid'];
Learn about PHP serialization here:
http://php.net/manual/en/function.serialize.php
http://php.net/manual/en/function.unserialize.php
What exactly are you trying to achieve? That string looks like a serialize()d one, so your best bet would be to unserialize() it
It looks like serialized string.
$data = unserialize('a:2:{s:4:"user";b:1;s:6:"userid";s:2:"48";}');
print_r($data['userid']);
Looks like that's a serialized associative array. You just need to use unserialize() to turn it back from a string into an array.
<?php
$arr = unserialize('a:2:{s:4:"user";b:1;s:6:"userid";s:2:"48";}');
echo $arr['userid'];
?>
The string I see is serialized array in PHP
To unserialize array do this
$obj = unserialize('a:2:{s:4:"user";b:1;s:6:"userid";s:2:"48";}');
echo $obj['userid'];
I have unserialized array then access array param by name

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