Create reusable chain function javascript

Question

I trying to create reusable chaining function, but I'm stuck. Common way c.plus(5).plus(2).execute() work fine, but I have no idea how to make this reusable like below. Do you have any idea how to do this?

 function chain() { this.i = 0; this.plus = (x) => { this.i = this.i + x; return this; }; this.execute = () => console.log(this.i); } const c = new chain(); const c1 = c.plus(5); c1.plus(2).execute(); // 7 c1.execute();// 7 instead of 5 

Answer 1

The problem with your current function is that when you call plus() , you are modifying i in the original object c .

Instead, return a new chain object each time you call plus(arg) , adding arg to the current value of i .

BTW it is customary in javascript to use TitleCase to name constructors. Usually chain would be Chain . FYI.

 function Chain() { this.i = 0; this.plus = (x) => { let c = new Chain(); ci = this.i + x; return c; }; this.execute = () => console.log(this.i); } const c = new Chain(); const c1 = c.plus(5); c1.plus(2).execute(); // 7 c1.execute();// 7 instead of 5 c.plus(2).plus(10).execute(); // 12