Consider following code:
mynamespace.myclass = function() {
this.myfunction = function() { alert("Original"); }
}
What I'm trying to do is to overwrite myfunction from outside of mynamespace.myclass declaration.
While adding new functions through prototype seems to work ok, if I define a function with the same name the original function doesn't get overwritten:
mynamespace.myclass.prototype.myfunction = function() {
alert("Overwritten");
}
Any ideas?
Introduction. It is true that JavaScript supports overriding, not overloading. When you define multiple functions that have the same name, the last one defined will override all the previously defined ones and every time when you invoke a function, the last defined one will get executed.
Given an HTML document and the task is to override the function, either predefined function or user-defined function using JavaScript. Approach: When we run the script then Fun() function called.
A JavaScript function is defined with the function keyword, followed by a name, followed by parentheses (). Function names can contain letters, digits, underscores, and dollar signs (same rules as variables).
That's because myfunction
is being added in the constructor, which happens after the prototype properties are added (so that the "Original" is in fact overwriting the "Overwritten").
You'll have to mimic this behaviour, by overwriting mynamespace.myclass
itself:
var oldClass = mynamespace.myclass; // Copy original before overwriting
mynamespace.myclass = function () {
// Apply the original constructor on this object
oldClass.apply(this, arguments);
// Now overwrite the target function after construction
this.myfunction = function () { alert("Overwritten"); };
};
mynamespace.prototype = oldClass.prototype; // Same prototype
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