So if I want to do something like five().plus().five().equals() // this should return 10
How can I achieve this? I understand method chaining when the functions return another function but what about when you want to use a value in the next function in the chain?
>Solution :
class Stack{
constructor(state=0){
this.state = state;
this.op = null;
}
pushVal(v){
switch(this.op){
case '+': this.state += v; break;
case '-': this.state -= v; break;
default: this.state = v; break;
}
}
plus(){
this.op = '+';
return this;
}
minus(){
this.op = '-';
return this;
}
equals(){
return this.state;
}
}
consts = {
five: 5,
six: 6,
seven: 7
};
for(const n in consts){
Stack.prototype[n] = function (){
this.pushVal(consts[n])
return this;
}
}
five = () => new Stack(5)
/// Now we can run what you want
console.log(five().plus().five().equals())
// and some extension of it
console.log(five().plus().five().minus().seven().equals())