Optional Arguments

optionalArguments.js

var sum = 0;
var undefinedCounter = 0;
function add() {
  var argsArr = [];
  for (var i=0;i<arguments.length;i++){
    argsArr.push(arguments[i]);
  }
  filterValueType(argsArr);
  if (argsArr.length < 2 && undefinedCounter < 1){
    sum = argsArr[0];
    return function(n){
      sum = sum + arguments[0];
      filterValueType(arguments);
      if (undefinedCounter > 0){
        return undefined;
      }else{
        return sum;
      }
    };
  }else{
    sum = argsArr[0] + argsArr[1];
    if (undefinedCounter > 0){
      return undefined;
    }else{
      return sum;
    }
  }
  function filterValueType(arrArgs){
    undefinedCounter = 0;
    for (var j=0;j<arrArgs.length;j++){
      if (typeof arrArgs[j] === 'string' || isArray(arrArgs[j]) || isNaN(arrArgs[j])){
        undefinedCounter = undefinedCounter + 1;
      }
    }
    return undefinedCounter;
  }
  function isArray(inputArr) {
    return inputArr.constructor.toString().indexOf("Array") > -1;
  }
}
add(2, 3);
// more example calls
// add(2, "3");
// add("http://bit.ly/IqT6zt");
// add(2)(3);
// add(2)([3]);

OptionalArguments.markdown

Optional Arguments

A function that sums two arguments together. If only one argument is provided, it returns a function that expects one argument and returns the sum. For example, add(2, 3) should return 5, while add(2) should return a function. Calling this returned function with a single argument will then return the sum. If either argument isn't a valid number, returns undefined.

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