


Detailed explanation of the constructor pattern of JS design patterns
This time I will bring you a detailed explanation of the constructor pattern of JS design pattern, what are the precautions when using the constructor pattern of JS design pattern, the following is a practical case, one Get up and take a look.
In the classic OOP language, the constructor (also called constructor) is a special method used to initialize an object. In JS, because everything is an object, object constructors are often mentioned.
The object constructor is used to create an object of a specified type (Class) and can accept parameters to initialize the properties and methods of the object.
Object creation
In JS, there are three commonly used methods for creating objects:
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However, this only creates three empty objects without any properties and methods. We can set properties and methods for objects through the following four methods.
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Basic constructor
We know that there is no concept of Class in JS, but it also supports using constructors to create objects.
By using the [new] keyword, we can make a function behave like a constructor and create its own object instance.
A basic constructor form is as follows:
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This is the simple constructor pattern. It has two main problems,
First, it is difficult to inherit; second, toString() is defined once for each object instance. As a function, it should be shared by every instance of the Car type.
Using prototype constructors
There is a very good feature in JS: prototype [Prototype],
Using it, when creating an object, all properties in the constructor prototype can be obtained by the object instance.
This way multiple object instances can share the same prototype.
We improve the previous Car example as follows:
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In the above example, the toString() method is shared by multiple Car object instances. .
I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!
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The above is the detailed content of Detailed explanation of the constructor pattern of JS design patterns. For more information, please follow other related articles on the PHP Chinese website!

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