console.log(add(1,2)(3))结果是6
let add = function(a,b){
return function(c){
return a+b+c
}
}
console.log(add(1,2)(3))
console.log(add(1)(2，3))结果是6
let add = function(a){
return function(b,c){
return a+b+c
}
}
console.log(add(1)(2,3))
