Before attempting to solve the below, read this.
Consider the code below:
function Foo1() {
this.foo = "foo1";
this.alertFoo = function() {
alert(this.foo);
}
}
function Foo2() {
this.foo = "foo2";
this.alertFoo = function() {
alert(this.foo);
}
}
function moo() {
var foo1 = new Foo1();
var foo2 = new Foo2();
foo1.alertFoo = new Foo2().alertFoo;
foo1.alertFoo();
}
What will be alerted when the function moo is called?
foo1.
The way “this”(context) is treated in JavaScript explains this behaviour.
When you say foo1.alertFoo = new Foo2().alertFoo, “this” of alertFoo no longer points to foo2’s this but to foo1’s this, because now the function alertFoo is executed in foo1’s context and not foo2’s.
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