保持状态处于咖喱状态

Question

Is there a way to keep some sort of internal state while writing a curried function?

For example, let's say I want to write a curried function that takes into account the number of times the function was called previously.

Ie addProgressively(3)(4)(5) = 1*3 + 2*4 + 3*5 = 26.

My approach is to add some counter that increments every time a new curried function is returned but I can't find a good way to keep track of that argument within the addProgressively function.

Answer 1

You could use another variable as closure for the factor.

 function addProgressively(x) { var factor = 1, sum = factor * x; function f(y) { factor++; sum += factor * y; return f; }; f.toString = function () { return sum; }; return f; } console.log(addProgressively(3)(4)(5));