PHP json_encode() Function

The PHP json_encode() function returns a string containing the JSON representation of the given value.

The encoding is affected by the supplied flags and additionally the encoding of float values depends on the value of serialize_precision.

Syntax

json_encode(value, flags, depth)

Parameters

Return Value

Returns a JSON encoded string on success or false on failure.

Example: json_encode() example

The example below shows how to use the json_encode() function with a PHP array.

<?php
//declaring an array
$arr = array('a' => 10, 'b' => 20, 'c' => 30);

//using json_encode() function to 
//encode into JSON string
$jsonObj = json_encode($arr);

//displaying the result
echo $jsonObj;
?>

The output of the above code will be:

{"a":10,"b":20,"c":30}

Example: json_encode() example with PHP object

The example below shows how to use this function with a PHP object.

<?php
//declaring a class
class person {     
}
   
//declaring an object
$p1 = new person();
   
//setting the object elements
$p1->name = "John";
$p1->email = "john@example.com";

//using json_encode() function to 
//encode into JSON string
$jsonObj = json_encode($p1);

//displaying the result
echo $jsonObj;
?>

The output of the above code will be:

{"name":"John","email":"john@example.com"}

Example: using flag parameter

Consider one more example which illustrates on using JSON_PRESERVE_ZERO_FRACTION option with this function.

<?php
var_dump(json_encode(12.0, JSON_PRESERVE_ZERO_FRACTION));
var_dump(json_encode(12.0));
?>

The output of the above code will be:

string(4) "12.0"
string(2) "12"