JSON.stringify Method (Windows Scripting - JScript)

Serializes a JScript value into JavaScript Object Notation (JSON) text.

Syntax

JSON.stringify(value [, replacer] [, space])

Arguments

• value
  Required. A JScript value, usually an object or array, to be serialized.

• replacer
  Optional. A function or array that filters and transforms the results.

  If replacer is a function, JSON.stringify calls the function, passing in the key and value of each member. The return value is serialized instead of the original value. If the function returns undefined, the member will be excluded from the serialization. The key for the root object is an empty string: "".

  If replacer is an array, only members with key values in the array will be serialized. The order of serialization is the same as the order of the keys in the array. The replacer array is ignored when the value argument is also an array.

• space
  Optional. Adds indentation, white space, and line break characters to the return-value JSON text to make it easier to read.

  If space is omitted, the return-value text is generated without any extra white space.

  If space is a number, the return-value text is indented with the specified number of white spaces at each level. If space is larger than 10, text is indented 10 spaces.

  If space is a non-empty string, such as '\t', the return-value text is indented with the characters in the string at each level.

  If space is a string that is longer than 10 characters, the first 10 characters are used.

Return Value

A string that contains the serialized JSON text.

Exceptions

Exception

Condition

Remarks

If the value that is being serialized has a toJSON method, the JSON.stringify method calls the toJSON method and uses the return value for serialization. If the return value of the toJSON method is undefined, the member will not be serialized. This enables an object to determine its own JSON representation.

Values that do not have JSON representations, such as undefined, will not be serialized. In objects, they will be dropped. In arrays, they will be replaced with null.

String values begin and end with a quotation mark. All Unicode characters may be enclosed in the quotation marks except for the characters that must be escaped by using a backslash. The following characters must be preceded by a backslash:

• Quotation mark (")

• Backslash (\)

• Backspace (b)

• Formfeed (f)

• Newline (n)

• Carriage return (r)

• Horizontal tab (t)

• Four-hexadecimal-digits (uhhhh)

Order of Execution

During the serialization process, if a toJSON method exists for the value argument, JSON.stringify first calls the toJSON method. If it does not exist, the original value is used. Next, if a replacer argument is provided, the value (original value or toJSON return-value) is replaced with the return-value of the replacer argument. Finally, white spaces are added to the value based on the optional space argument to generate the final serialized JSON text.

This example uses JSON.stringify to serialize the contact object to JSON text. The memberfilter array is defined so that only the surname and phone members are serialized. The firstname member is omitted.

var contact = new Object();
contact.firstname = "Jesper";
contact.surname = "Aaberg";
contact.phone = ["555-0100", "555-0120"];

var memberfilter = new Array();
memberfilter[0] = "surname";
memberfilter[1] = "phone";
var jsonText = JSON.stringify(contact, memberfilter, "\t");
/* the value of jsonText is
'{
    "surname": "Aaberg",
    "phone": [
        "555-0100",
        "555-0120"
    ]
}'
*/

This example uses JSON.stringify to serialize an array. The replaceToUpper function converts every string in the array to uppercase.

var continents = new Array();
continents[0] = "Europe";
continents[1] = "Asia";
continents[2] = "Australia";
continents[3] = "Antarctica";
continents[4] = "North America";
continents[5] = "South America";
continents[6] = "Africa";

var jsonText = JSON.stringify(continents, replaceToUpper);
/* the value of jsonText is:
'"EUROPE,ASIA,AUSTRALIA,ANTARCTICA,NORTH AMERICA,SOUTH AMERICA,AFRICA"'
*/

function replaceToUpper(key, value) {
    return value.toString().toUpperCase();
}

This example uses the toJSON method to serialize string member values in uppercase.

var contact = new Object();
contact.firstname = "Jesper";
contact.surname = "Aaberg";
contact.phone = ["555-0100", "555-0120"];

contact.toJSON = function(key)
 {
    var replacement = new Object();
    for (var val in this)
    {
        if (typeof (this[val]) === 'string')
            replacement[val] = this[val].toUpperCase();
        else
            replacement[val] = this[val]
    }
    return replacement;
};

var jsonText = JSON.stringify(contact);

/* The value of jsonText is:
'{"firstname":"JESPER","surname":"AABERG","phone":["555-0100","555-0120"]}'
*/

Requirements

Version 5.8

Internet Explorer 8 Release Changes

After the initial release of Internet Explorer 8, an update was made to the JSON feature. The update improved JSON interoperability in conformance with the ECMAScript 5 standard. The update applies to Internet Explorer 8. For more information about the update, see KB976662.

The following table summarizes changes to the JSON.stringify method. Most of the changes apply to invalid argument values or to other irregular situations.

Change History

See Also

JSON.parse Method
toJSON Method
JSON Object
JScript Methods