(33)Arguments Optional

Arguments Optional
33-ий день программы "#100 Days Of Code"

Create a function that sums two arguments together. If only one argument is provided, then return a function that expects one argument and returns the sum.

For example, addTogether(2, 3) should return 5, and addTogether(2) should return a function.

Calling this returned function with a single argument will then return the sum:

var sumTwoAnd = addTogether(2);

sumTwoAnd(3) returns 5.

If either argument isn't a valid number, return undefined.

• Closures
• Arguments object

function addTogether() {
  var results;
  if(arguments.length <=3){
    var a1 = arguments[0];
    var a2 = arguments[1];
    if(typeof(a2)==='number'){
      if(typeof(a1) ==='number'){
      
        results = a1 +a2;
      }
    } else if(a2===undefined && typeof(a1)==='number'){
      return function(a2){
        if(typeof(a2)==='number'){
          return a1 + a2;
        }
        else return results;
      };
    }
  }
  return results;
}

addTogether(2,3);

Ответы:

addTogether(2, 3)
return 5.

addTogether(2)(3)
return 5.

addTogether("http://bit.ly/IqT6zt")
return undefined.

addTogether(2, "3")
return undefined.

addTogether(2)([3])
return undefined.