What does it mean when a javascript function is declared in the following way:
JSON.stringify = JSON.stringify || function (obj)
{
//stuff
};
How is the above different from just declaring it like below?
function stringify(obj)
{
//stuff
}
function stringify will declare the function in the global scope (if you're not already inside another scope, such as another function or a hash) or the scope you're currently in.
Example:
function a() { ... } /* global scope */
function a() { function b() { ... } /* scope of the a() function */ }
JSON.stringify = function will define the function on the JSON object.
Example:
JSON = {}
JSON.stringify = function() { ... } /* you can now call stringify() on the JSON object */
JSON.stringify || function will only define it if it was not previously defined.
Example:
JSON = {}
JSON.stringify = function() { ... }
JSON.stringify = JSON.stringify || function() { ... } /* will not be replaced */