JavaScript JSON stringify() Method
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JavaScript JSON stringify() Method

❮ JavaScript JSON Object

Example

Stringify a JavaScript object:

var obj = { "name":"John", "age":30, "city":"New York"};
var myJSON = JSON.stringify(obj);
document.getElementById("demo").innerHTML = myJSON;
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More "Try it Yourself" examples below.


Definition and Usage

The JSON.stringify() method converts JavaScript objects into strings.

When sending data to a web server the data has to be a string.


Browser Support

The numbers in the table specify the first browser version that fully supports the method.

Method
stringify() 4.0 8.0 3.5 4.0 11.5

Syntax

JSON.stringify(obj, replacer, space)

Parameter Values

Parameter Description
obj Required. The value to convert to a string
replacer Optional. Either a function or an array used to transform the result. The replacer is called for each item.
space Optional. Either a String or a Number.
A string to be used as white space (max 10 characters),
or a Number, from 0 to 10, to indicate how many space characters to use as white space.


Technical Details

Return Value: A String
JavaScript Version: ECMAScript 1

More Examples

Example

Using the replacer function:

/*replace the value of "city" to upper case:*/
var obj = { "name":"John", "age":"39", "city":"New York"};
var text = JSON.stringify(obj, function (key, value) {
    if (key == "city") {
      return value.toUpperCase();
    } else {
      return value;
    }
});
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Example

Using the space parameter:

/*Insert 10 space characters for each white space:*/
var obj = { "name":"John", "age":"39", "city":"New York"};
var text = JSON.stringify(obj, null, 10);
Try it Yourself »

Example

Using the space parameter:

/*Insert the word SPACE for each white space:*/
var obj = { "name":"John", "age":"39", "city":"New York"};
var text = JSON.stringify(obj, null, "SPACE");
Try it Yourself »

❮ JavaScript JSON Object