json_encode

Description
Syntax
Examples
Links

Description

The json_encode of JSON for PHP returns the JSON representation of a value.

Syntax

json_encode(
    mixed $value,
    int $flags = 0,
    int $depth = 512
): string|false

Parameters

value

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

All string data must be UTF-8 encoded.

NOTE: PHP implements a superset of JSON as specified in the original RFC 7159.

Bitmask consisting of JSON_FORCE_OBJECT, JSON_HEX_TAG, JSON_HEX_AMP, JSON_HEX_APOS, JSON_HEX_QUOT, 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_INVALID_UTF8_IGNORE, JSON_INVALID_UTF8_SUBSTITUTE, JSON_THROW_ON_ERROR.

depth

Set the maximum depth. Must be greater than zero.

Return

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

Examples

1 · value

<?

$value =
[
    "a" => 1,
    "b" => 2,
    "c" => 3
];

$return = json_encode($value);

echo $return;

{"a":1,"b":2,"c":3}

2 · flags · 0

<?

$value =
[
    1,
    2,
    3
];
$flags = 0;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

[1,2,3]
[1,2,3]

3 · flags · JSON_FORCE_OBJECT

<?

$value =
[
    1,
    2,
    3
];
$flags = JSON_FORCE_OBJECT;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

<!doctype html>
<html>
<head>
    <title>PHP</title>
    <style>
        html, a
        {
            background-color: rgb(255 0 255 / 0.1);
        }
        a
        {
            color: purple;
            transition-duration: 1s;

            &:hover
            {
                background-color: rgb(0 0 0 / 0.1);
                color: black;
                text-decoration-color: transparent;
            }
        }
    </style>
</head>
<body>
    <a href="/php/">PHP</a>
    <script>
        function myfunction(myparameter)
        {
            const mytarget = myparameter.target;
            const mystyle = mytarget.style;
            mystyle.position = "absolute";
            if(mystyle.left == "")
            {
                mystyle.left = "8px";
                mystyle.top = "8px";
            }
            mystyle.left = `${Math.random() * (window.innerWidth - mytarget.offsetWidth)}px`;
            mystyle.top = `${Math.random() * (window.innerHeight - mytarget.offsetHeight)}px`;
        }
        document.querySelector("a").addEventListener("mouseout", myfunction);
    </script>
</body>
</html>

4 · flags · JSON_HEX_TAG

<?

$value = "<>";
$flags = JSON_HEX_TAG;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

"<>"
"\u003C\u003E"

5 · flags · JSON_HEX_AMP

<?

$value = "&";
$flags = JSON_HEX_AMP;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

"&"
"\u0026"

6 · flags · JSON_HEX_APOS

<?

$value = "'";
$flags = JSON_HEX_APOS;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

"'"
"\u0027"

7 · flags · JSON_HEX_QUOT

<?

$value = '"';
$flags = JSON_HEX_QUOT;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

"\""
"\u0022"

8 · flags · JSON_NUMERIC_CHECK

<?

$value =
[
    "123",
    "-123",
    "+123",
    "12e3",
    "0.0000123"
];
$flags = JSON_NUMERIC_CHECK;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

["123","-123","+123","12e3","0.0000123"]
[123,-123,123,12000,1.23e-5]

9 · flags · JSON_PARTIAL_OUTPUT_ON_ERROR

<?

$value =
[
    "partial",
    "output",
    "\xaa"
];
$flags = JSON_PARTIAL_OUTPUT_ON_ERROR;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

var_export($return1);
echo PHP_EOL . $return2;

false
["partial","output",null]

10 · flags · JSON_PRESERVE_ZERO_FRACTION

<?

$value = 1.0;
$flags = JSON_PRESERVE_ZERO_FRACTION;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

1
1.0

11 · flags · JSON_PRETTY_PRINT

<?

$value =
[
    1,
    2,
    3
];
$flags = JSON_PRETTY_PRINT;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

[1,2,3]
[
    1,
    2,
    3
]

12 · flags · JSON_UNESCAPED_LINE_TERMINATORS

<?

$value = "\xe2\x80\xa8\xe2\x80\xa9";
$flags = JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_LINE_TERMINATORS;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

"\u2028\u2029"
"  "

13 · flags · JSON_UNESCAPED_SLASHES

<?

$value = "/";
$flags = JSON_UNESCAPED_SLASHES;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

"\/"
"/"

14 · flags · JSON_UNESCAPED_UNICODE

<?

$value = "·";
$flags = JSON_UNESCAPED_UNICODE;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

echo $return1 . PHP_EOL . $return2;

"\u00b7"
"·"

15 · flags · JSON_INVALID_UTF8_IGNORE

<?

$value = "\xaa";
$flags = JSON_INVALID_UTF8_IGNORE;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

var_export($return1);
echo PHP_EOL . $return2;

false
""

16 · flags · JSON_INVALID_UTF8_SUBSTITUTE

<?

$value = "\xaa";
$flags = JSON_INVALID_UTF8_SUBSTITUTE;

$return1 = json_encode($value);
$return2 = json_encode($value, $flags);

var_export($return1);
echo PHP_EOL . $return2;

false
"\ufffd"

17 · depth

<?

$value =
[
    1,
    2,
    [
        1,
        2,
        [
            1,
            2
        ]
    ]
];
$flags = 0;
$depth = 3;

$return = json_encode($value, $flags, $depth);

echo $return;

[1,2,[1,2,[1,2]]]