Arguments Optional-freecodecamp Algorithm Topics

Arguments Optional

1. Requirements

• Create a function that calculates the sum of two parameters. If there is only one argument, a function is returned, and the function requests a parameter and then returns the result of the sum.
• If none of the two parameters is a valid number, the undefined is returned.

2. Ideas

• Determine the number of input data
• The number of data is 1, the data type is judged,
  • Type is a number: Assign this data to a, return a function, this function requires a data B, judge the type of B, is the number returned A+B, not the number, return undefined;
  • Type is not a number: returns undefined.
• The number of data is 2, the data type is judged, both are numeric, return two data and, otherwise, return undefined.

3. Code

function add() {  if(arguments.length===1){      if(typeof(arguments[0])==='number'){        var a=arguments[0];          return function(b){            if(typeof(b)==='number'){              return a+b;            }            else{              return undefined;            }          };      }      else{        return undefined;      }  }  else if(arguments.length===2){    if(typeof(arguments[0])==='number' && typeof(arguments[1])==='number'){      return arguments[0]+arguments[1];    }    else{      return undefined;    }  }}add(2)(2);

4. RELATED LINKS

• Https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Functions/arguments
• Https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Closures

Arguments Optional-freecodecamp Algorithm Topics