CODEWITHSUNDEEP
javascriptobjectmathreturn
prasanth
prasanth

Reputation: 22500

Pass one object result to another object function like chain

I have one simple object calculation function .I was pass the object resultant data in to another object function like the chain reaction

example like:

str.replace().replace().replace() They will pass the resultant data of first replace to 2nd replace like the chain reaction.

So i want to created the below code .But not working in my case .

See the below snippet

var m=function(data){
  return {
       str :data,
       plus:function(b){
            this.str = this.str+b;
           return this.str;
         },
      min:function(a){
            this.str = this.str-a
            return this.str;
         }
    }
  }

console.log(m(5).plus(1).min(3))

If 5 add with 1 is 6 .Then pass the 6 into min() function for reduce 3 .finally console.log result 3 .But It have some here .Please help to solve my problem.

Thanks

Upvotes: 2

Views: 232

Answers (3)

NVRM
NVRM

Reputation: 13120

Another closer way, we can return this separately, at initialisation, and every other method calls.

Doing it this way is a real chain, as this called in the plus and min function is the incoming object, it's not a recomposition.

We often see both styles.

function m(n) {
  this.value = n.value
  this.plus = (n) => {this.value = this.value + n.value; return this}
  this.min = (n) => {this.value = this.value - n.value; return this}
  return this // Only at initialisation
}

console.log(m({value: 5}).plus({value: 1}).min({value: 3}).value)

Upvotes: 0

Nina Scholz
Nina Scholz

Reputation: 386680

I suggest to use an object and return that object after a method call. For better use, you could implement toString and valueOf methods to use the return value directly.

What you need is to return the whole object, for all methods which a chainable.

var m = function(value){
    var obj = {
            value: value,
            plus: function (b) {
                obj.value += b;
                return obj;
            },
            min: function(a) {
                obj.value -= a;
                return obj;
            },
            toString: function () { return obj.value; },
            valueOf: function () { return obj.value; }
        }
        return obj;
    }

console.log(m(5).plus(1).min(3).value);
alert(m(5).plus(1).min(3));
console.log(m(3).plus(7) - m(5).min(1));

Upvotes: 2

Himanshu Tanwar
Himanshu Tanwar

Reputation: 906

var m=function(data){
  return {
       str :data,
       plus:function(b){
            this.str = this.str+b;
           return this;
         },
      min:function(a){
            this.str = this.str-a
            return this;
         }
    }
  }

console.log(m(5).plus(1).min(3).str)

For creating chain like method calls you need to return 'this' from the function after which you want to the chain to continue

Upvotes: 1

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