//  1.粗暴版
    function add(a) {
      return function (b) {
        return function (c) {
          return a + b + c;
        }
      }
    }
    console.log(add(1)(2)(3));

    //2) 柯里化解決方案
    // 引數長度固定
    const curry = (fn) => (juedge = (...args) => args.length === fn.length ?
     fn(...args) : (...arg) 
 
=> judge(...args, ...arg));

     const add=(a,b,c)=>a+b+c;
     const curryAdd=curry(add);
     console.log(curryAdd(1)(2)(3))

    var add = function (m) {
      var temp = function (n) {
        return add(m + n);
      }
      temp.toString = function () {
        return m;
      }
      return
 
 temp;
    };
    console.log(add(3)(4)(5)); // 12
    console.log(add(3)(6)(9)(25)); // 43

    // 利用了函式的柯里化和閉包特性
    function add(...arg) {
      let a = [...arg];
      _add = function (...innerArg) {
        if (innerArg.length === 0) {
          return a.reduce(function (a, b) { return a + b })
        } 
 
else {
          console.log(innerArg);
          [].push.apply(a, innerArg)
          return _add;
        }
      }
      return _add
    }
  console.log(add(1)(2,2,3)())   // 6