How to Safely Reference Properties Within the Same JavaScript Object?

How to Reference Properties in the Same Object

In JavaScript, an object can refer to its own values by storing a reference to its properties. However, accessing properties within the same object using dot or bracket notation can sometimes lead to undefined errors.

Consider the following code:

var obj = {
  key1: "it ",
  key2: key1 + " works!"
};

alert(obj.key2);

This code will result in a "key1 is not defined" error. This is because at the time of referencing key2, the key1 property hasn't been defined yet.

Solution:

To circumvent this issue, access the property using a function.

var obj = {
  key1: "it ",
  key2: function() {
    return this.key1 + " works!";
  }
};

alert(obj.key2());

In this revised code, key2 is declared as a function within the object. When the key2 function is invoked, it uses the this keyword to access the key1 property within the same object. This approach allows you to reference properties within the same object even when they are defined in a different order.

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