PHP and JSON
What is JSON?
JSON stands for JavaScript Object Notation, and is a syntax for storing and exchanging data.
Since the JSON format is a text-based format, it can easily be sent to and from a server, and used as a data format by any programming language.
PHP and JSON
PHP has some built-in functions to handle JSON.
First, we will look at the following two functions:
- json_encode()
- json_decode()
PHP - json_encode()
The json_encode() function is used to encode a value to JSON format.
Example
This example shows how to encode an associative array into a JSON object:
<?php
$age = array("Peter"=>35, "Ben"=>37, "Joe"=>43);
echo json_encode($age);
?>
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Example
This example shows how to encode an indexed array into a JSON array:
<?php
$cars = array("Volvo", "BMW", "Toyota");
echo json_encode($cars);
?>
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PHP - json_decode()
The json_decode() function is used to decode a JSON object into a PHP object or an associative array.
Example
This example decodes JSON data into a PHP object:
<?php
$jsonobj = '{"Peter":35,"Ben":37,"Joe":43}';
var_dump(json_decode($jsonobj));
?>
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The json_decode() function returns an object by default. The json_decode() function has a second parameter, and when set to true, JSON objects are decoded into associative arrays.
Example
This example decodes JSON data into a PHP associative array:
<?php
$jsonobj = '{"Peter":35,"Ben":37,"Joe":43}';
var_dump(json_decode($jsonobj,
true));
?>
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PHP - Accessing the Decoded Values
Here are two examples of how to access the decoded values from an object and from an associative array:
Example
This example shows how to access the values from a PHP object:
<?php
$jsonobj = '{"Peter":35,"Ben":37,"Joe":43}';
$obj = json_decode($jsonobj);
echo $obj->Peter;
echo $obj->Ben;
echo $obj->Joe;
?>
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Example
This example shows how to access the values from a PHP associative array:
<?php
$jsonobj = '{"Peter":35,"Ben":37,"Joe":43}';
$arr = json_decode($jsonobj, true);
echo $arr["Peter"];
echo $arr["Ben"];
echo $arr["Joe"];
?>
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PHP - Looping Through the Values
You can also loop through the values with a foreach() loop:
Example
This example shows how to loop through the values of a PHP object:
<?php
$jsonobj = '{"Peter":35,"Ben":37,"Joe":43}';
$obj = json_decode($jsonobj);
foreach($obj
as $key => $value) {
echo $key . " => " . $value . "<br>";
}
?>
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Example
This example shows how to loop through the values of a PHP associative array:
<?php
$jsonobj = '{"Peter":35,"Ben":37,"Joe":43}';
$arr = json_decode($jsonobj, true);
foreach($arr as $key => $value) {
echo $key . " => " . $value
. "<br>";
}
?>
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