Created
February 20, 2014 11:10
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'this' in a method invocation and testing when a function is added to the object.
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| // You need log4javascript for the logging to work | |
| // Or use the console, if log4javascript is not available | |
| if (typeof log !== 'Object') { | |
| log = { | |
| debug: function (message) { | |
| console.log(message); | |
| } | |
| } | |
| } | |
| var object1 = { | |
| $get: function () { | |
| log.debug(this); | |
| this.f = function () { | |
| return 42; | |
| } | |
| } | |
| } | |
| // When calling $get() directly 'this' points to object1 itself where function f() is not yet added | |
| object1.$get(); | |
| // But calling f() is possible, because $get() added it | |
| object1.f() | |
| // Creating a new instance with prototype inheritance | |
| function constr() {}; | |
| constr.prototype = object1; | |
| var instance = new constr(); | |
| // Now 'this' inside $get() will point to the new instance where function f() is already added | |
| // instance.$get(); | |
| log.debug(instance.f()); |
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