2020-03-12 实现add方法

[fanmingfei]

function add(number) {
}

add(1)(2)() // 3， 1+2 = 3 

add(1)(2)(3)() // 6， 1+2+6 =6

add(5)(8)(8)(6)(5)() // 32，5+8+8+6+5 = 32
// ...  以此类推，后面的执行次数不限

实现 该 add 方法

[Vince-9]

function add(v) {
  if(v === undefined) return 0;
  let sum = v;
  return function(val){
    if(val === undefined) return sum;
    return add(val + sum);
  }
}

[xiaosen7]

const add = (n, S = n) => typeof n !== 'undefined' ? m => add(m, isNaN(m) ? S :S+m) : S;

[jef0317]

function add(args){
return function(num) {
if(num){
return add(args+num)
}else{
return args
}
}
}

[joker1148]

function add(v){
    if(v === undefined) return;
    else{
        let sum = v
        return (val)=>{
            if(val === undefined) return sum
            return add(sum+val)
        }
    } 
}
console.log(add(1)(2)(3)().toString())
借鉴了一下下哈哈

[SunYiwen]

function add(num) {
    let sum;
    if(arguments.length === 0) {
        sum=0;
        return sum;
    }
    else{
        sum = num;
        return function innerAdd(number) {
            if(arguments.length === 0){
                return sum;
            }
            else{
                return add(number + sum);
            }
        }
    }
}

[LiZhaji]

function add(number){
  if (number!== 0 && !number) return 0
  return function (num) {
    if (num) return add(number + num)
    return number
  }
}

[fanmingfei]

function add(number = 0){
  return function add2(num) {
    number += num || 0
    if (num===undefined) return number
    return add2
  }
}

[liuyingbin19222]

function add(num){
    var sum = 0;
    sum = sum + num;
    return function Fun(numB){
        if(arguments.length === 0){
            return sum;
        }else {
            sum = sum + numB;
            return Fun;
        }
    }
}