PHP.nl

json_encode

json_encode

Returns the JSON representation of a value

 **json_encode** mixed $value int $flags int $depth

Returns a string containing the JSON representation of the supplied . If the parameter is an array or object, it will be serialized recursively. value

If a value to be serialized is an object, then by default only publicly visible properties will be included. Alternatively, a class may implement to control how its values are serialized to . JsonSerializable

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

value The being encoded. Can be any type except a resource. value

All string data must be UTF-8 encoded.

flags Bitmask consisting of , , , , , , , , , , , , , , . The behaviour of these constants is described on the page. JSON_FORCE_OBJECT``JSON_HEX_QUOT``JSON_HEX_TAG``JSON_HEX_AMP``JSON_HEX_APOS``JSON_INVALID_UTF8_IGNORE``JSON_INVALID_UTF8_SUBSTITUTE``JSON_NUMERIC_CHECK``JSON_PARTIAL_OUTPUT_ON_ERROR``JSON_PRESERVE_ZERO_FRACTION``JSON_PRETTY_PRINT``JSON_UNESCAPED_LINE_TERMINATORS``JSON_UNESCAPED_SLASHES``JSON_UNESCAPED_UNICODE``JSON_THROW_ON_ERRORJSON constants

depthSet the maximum depth. Must be greater than zero.

Returns a JSON encoded string on success return.falseforfailure.

Voorbeeld: A example

<?php
$arr = array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5);

echo json_encode($arr);
?>

{"a":1,"b":2,"c":3,"d":4,"e":5}

**Voorbeeld: A example showing some flags in use **

<?php
$a = array('<foo>',"'bar'",'"baz"','&blong&', "\xc3\xa9");

echo "Normal: ",  json_encode($a), "\n";
echo "Tags: ",    json_encode($a, JSON_HEX_TAG), "\n";
echo "Apos: ",    json_encode($a, JSON_HEX_APOS), "\n";
echo "Quot: ",    json_encode($a, JSON_HEX_QUOT), "\n";
echo "Amp: ",     json_encode($a, JSON_HEX_AMP), "\n";
echo "Unicode: ", json_encode($a, JSON_UNESCAPED_UNICODE), "\n";
echo "All: ",     json_encode($a, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP | JSON_UNESCAPED_UNICODE), "\n\n";

$b = array();

echo "Empty array output as array: ", json_encode($b), "\n";
echo "Empty array output as object: ", json_encode($b, JSON_FORCE_OBJECT), "\n\n";

$c = array(array(1,2,3));

echo "Non-associative array output as array: ", json_encode($c), "\n";
echo "Non-associative array output as object: ", json_encode($c, JSON_FORCE_OBJECT), "\n\n";

$d = array('foo' => 'bar', 'baz' => 'long');

echo "Associative array always output as object: ", json_encode($d), "\n";
echo "Associative array always output as object: ", json_encode($d, JSON_FORCE_OBJECT), "\n\n";
?>

Normal: ["<foo>","'bar'","\"baz\"","&blong&","\u00e9"]
Tags: ["\u003Cfoo\u003E","'bar'","\"baz\"","&blong&","\u00e9"]
Apos: ["<foo>","\u0027bar\u0027","\"baz\"","&blong&","\u00e9"]
Quot: ["<foo>","'bar'","\u0022baz\u0022","&blong&","\u00e9"]
Amp: ["<foo>","'bar'","\"baz\"","\u0026blong\u0026","\u00e9"]
Unicode: ["<foo>","'bar'","\"baz\"","&blong&","é"]
All: ["\u003Cfoo\u003E","\u0027bar\u0027","\u0022baz\u0022","\u0026blong\u0026","é"]

Empty array output as array: []
Empty array output as object: {}

Non-associative array output as array: [[1,2,3]]
Non-associative array output as object: {"0":{"0":1,"1":2,"2":3}}

Associative array always output as object: {"foo":"bar","baz":"long"}
Associative array always output as object: {"foo":"bar","baz":"long"}

Voorbeeld: JSON_NUMERIC_CHECK option example

<?php
echo "Strings representing numbers automatically turned into numbers".PHP_EOL;
$numbers = array('+123123', '-123123', '1.2e3', '0.00001');
var_dump(
 $numbers,
 json_encode($numbers, JSON_NUMERIC_CHECK)
);
echo "Strings containing improperly formatted numbers".PHP_EOL;
$strings = array('+a33123456789', 'a123');
var_dump(
 $strings,
 json_encode($strings, JSON_NUMERIC_CHECK)
);
?>

Strings representing numbers automatically turned into numbers
array(4) {
  [0]=>
  string(7) "+123123"
  [1]=>
  string(7) "-123123"
  [2]=>
  string(5) "1.2e3"
  [3]=>
  string(7) "0.00001"
}
string(28) "[123123,-123123,1200,1.0e-5]"
Strings containing improperly formatted numbers
array(2) {
  [0]=>
  string(13) "+a33123456789"
  [1]=>
  string(4) "a123"
}
string(24) "["+a33123456789","a123"]"

Voorbeeld: Sequential versus non-sequential array example

<?php
echo "Sequential array".PHP_EOL;
$sequential = array("foo", "bar", "baz", "blong");
var_dump(
 $sequential,
 json_encode($sequential)
);

echo PHP_EOL."Non-sequential array".PHP_EOL;
$nonsequential = array(1=>"foo", 2=>"bar", 3=>"baz", 4=>"blong");
var_dump(
 $nonsequential,
 json_encode($nonsequential)
);

echo PHP_EOL."Sequential array with one key unset".PHP_EOL;
unset($sequential[1]);
var_dump(
 $sequential,
 json_encode($sequential)
);
?>

Sequential array
array(4) {
  [0]=>
  string(3) "foo"
  [1]=>
  string(3) "bar"
  [2]=>
  string(3) "baz"
  [3]=>
  string(5) "blong"
}
string(27) "["foo","bar","baz","blong"]"

Non-sequential array
array(4) {
  [1]=>
  string(3) "foo"
  [2]=>
  string(3) "bar"
  [3]=>
  string(3) "baz"
  [4]=>
  string(5) "blong"
}
string(43) "{"1":"foo","2":"bar","3":"baz","4":"blong"}"

Sequential array with one key unset
array(3) {
  [0]=>
  string(3) "foo"
  [2]=>
  string(3) "baz"
  [3]=>
  string(5) "blong"
}
string(33) "{"0":"foo","2":"baz","3":"blong"}"

Voorbeeld: option example

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

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

Opmerking: > In the event of a failure to encode, can be used to determine the exact nature of the error. json_last_error

Opmerking: > When encoding an array, if the keys are not a continuous numeric sequence starting from 0, all keys are encoded as strings, and specified explicitly for each key-value pair.

Opmerking: > Like the reference JSON encoder, will generate JSON that is a simple value (that is, neither an object nor an array) if given a string, integer, float or boolean as an input . While most decoders will accept these values as valid JSON, some may not, as the specification is ambiguous on this point. json_encode``value

To summarise, always test that your JSON decoder can handle the output you
generate from .

json_encode

JsonSerializable``json_decode``json_last_error``json_last_error_msg``serialize

Vorige ← json_decode Volgende json_last_error_msg →

Documentatie