How does the replacer argument function extract keys and values from an object's value and map them to its key and value arguments in the JSON.stringify(value, replacer, space) method?
I have grasped that the key of the object becomes the key parameter of the replacer function and the value becomes the value parameter of this function.
let user = { name: "anup", age: 22 };
JSON.stringify(user, function(key, value) {
if (typeof value === "string") { return undefined; }
return value;
}, null);
In this code snippet, 'name' becomes the key of the replacer function and '"anup"' becomes the value of the replacer function. It is clear how this mapping works technically, but my question remains - how is this dynamic mapping achieved?
Typically, when we call a method, we pass arguments to that method during the method call, like so:
function a(c, d) {
// logic
}
a(2, 3);
But in the stringify method, we are not explicitly passing anything to the replacer function or callback function. So, how exactly is this mapping process orchestrated?
As I am relatively new to the world of JavaScript, there are some concepts that I struggle to fully grasp. Any guidance you could provide on this matter would be greatly appreciated!