Convert a JavaScript object into a string with JSON.stringify().
JSON.stringify()
Stringify a JavaScript Object
Imagine we have this object in JavaScript:
var obj = { "name":"John", "age":30, "city":"New York"};
Use the JavaScript function JSON.stringify() to convert it into a string.
var myJSON = JSON.stringify(obj);
The result will be a string following the JSON notation.
myJSON is now a string, and ready to be sent to a server:
Example
var obj = { "name":"John", "age":30, "city":"New York"};
var myJSON = JSON.stringify(obj);
document.getElementById("demo").innerHTML = myJSON;
You will learn how to send JSON to the server in the next chapter.
Stringify a JavaScript Array
It is also possible to stringify JavaScript arrays:
Imagine we have this array in JavaScript:
var arr = [ "John", "Peter", "Sally", "Jane" ];
Use the JavaScript function JSON.stringify() to convert it into a string.
var myJSON = JSON.stringify(arr);
The result will be a string following the JSON notation.
myJSON is now a string, and ready to be sent to a server:
Example
var arr = [ "John", "Peter", "Sally", "Jane" ];
var myJSON = JSON.stringify(arr);
document.getElementById("demo").innerHTML = myJSON;
Exceptions
Stringify Dates
In JSON, date objects are not allowed. The JSON.stringify() function will convert any dates into strings.
Example
var obj = { "name":"John", "today":new Date(), "city":"New York"};
var myJSON = JSON.stringify(obj);
document.getElementById("demo").innerHTML = myJSON;
You can convert the string back into a date object at the receiver.
Stringify Functions
In JSON, functions are not allowed as object values.
The JSON.stringify() function will remove any functions from a JavaScript object, both the key and the value:
Example
var obj = { "name":"John", "age":function () {return 30;}, "city":"New York"};
var myJSON = JSON.stringify(obj);
document.getElementById("demo").innerHTML = myJSON;
This can be omitted if you convert your functions into strings before running the JSON.stringify() function.
Example
var obj = { "name":"John", "age":function () {return 30;}, "city":"New York"};
obj.age = obj.age.toString();
var myJSON = JSON.stringify(obj);
document.getElementById("demo").innerHTML = myJSON;
Use this tool to edit, convert, format, and validate JSON: JSON formatter online tool
