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Method chaining in javascript

isiakaabd profile image ☪ REMLAD ™⚜ ・2 min read

Method is a function that is a property of an object. It is also a property containing a function definition.
let's consider the example below

Var car ={
Color: “red”,
brand: “Toyota”,
description: function (){
This.brand  + "is a  Motor Corporation is a Japanese multinational automotive manufacturer"
}
}

// description is a property of a car that is also a function. So a function inside an object is called METHOD.
 //Calling 
console.log(car.description())
// Toyota is a  Motor Corporation is a Japanese multinational automotive manufacturer

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If we have 5 methods in the object. We end up with something like this:
car.description()
car.description()
car.description()
car.description()
car.description()

Could you see that car is unnecessarily repeated and doesn’t seems neat and could take lines of code? We can get rid of that by using a mechanism called METHOD CHAINING.

Method chaining is the mechanism of calling a method on another method of the same object. This ensures a cleaner and readable code. Method chaining uses this keyword in the object's class to access its methods. In javascript, the this keyword refers to the current object in which it is called. When a method returns this, it simply returns an instance of the object in which it is returned. in another word, to chain methods together, we need to make sure that each method we define has a return value so that we can call another method on it.

Let's write some code

Class chaining{
    Method1(){
    console.log(method1)
    return this
    }

    Method2(){
    console.log(method2)
    return this
    }

}

 Const chaining_obj = new chaining()
 chaining_obj
 .mathod1()
 .method2()

//output
method1
method2


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let's consider this example

class Arithmetic {
  constructor() {
    this.value = 0;
  }
  sum(...args) {
    this.value = args.reduce((sum, current) => sum + current, 0);
    return this;
  }
  addition(value) {
    this.value = this.value + value;
    return this;
  }
  subtraction(value) {
    this.value = this.value - value;
    return this;
  }
  average(...args) {
    this.value = args.length? (this.sum(...args).value) / 
  args.length: undefined;
    return this;
  }
}


const Arithmetic 1= new Arithmetic()
Arithmetic1
  .sum(1, 3, 6)   // => { value: 10 } 
  .subtract(3)   // => { value: 7 }
  .add(4)        // => { value: 11 }
  .value         // => 11 


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That's the entire process of method chaining in Javascript.
Thanks for reading!!

Discussion (4)

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csulit profile image
Christian Angelo M Sulit

Short but helpful article 👌

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isiakaabd profile image
☪ REMLAD ™⚜ Author

Thanks Christiian

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unclebigbay profile image
Ayodele Samuel Adebayo(Uncle BigBay)

Interesting and helpful read, thanks Remlad

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isiakaabd profile image
☪ REMLAD ™⚜ Author

Thanks for the feedback Uncle Bigbay