JavaScript Road Trip Part 3 Level 2 Challenge 4

jsClosures.js

function mystery(input) {
  var secret = 4;
  input += 2;
  function mystery2(multiplier) {
    multiplier *= input;
    return secret * multiplier;
  }
  return mystery2;
}

function mystery3(param) {
  function mystery4(bonus) {
    return param(6) + bonus;
  }
  return mystery4;
}

var hidden = mystery(3);
var jumble = mystery3(hidden);
var result = jumble(2);

jsClosures.md

Calculate the final value of the result variable and alert the value as a number using one line of code.

function mystery(input) {
  var secret = 4;
  input += 2;
  function mystery2(multiplier) {
    multiplier *= input;
    return secret * multiplier;
  }
  return mystery2;
}

function mystery3(param) {
  function mystery4(bonus) {
    return param(6) + bonus;
  }
  return mystery4;
}

var hidden = mystery(3);

calling mystery3 gives us return mystery2 with the parameter 3 as the input:

function mystery2(multiplier) {
  multiplier *= 5;
  return secret * multiplier;
}

Next we have jumble, which takes hidden as a parameter, which is really just mystery2 with parameters passed in as above. So, we pass mystery2 as the param parameter in mystery3:

var jumble = mystery3(hidden);

function mystery4(bonus) {
  return mystery2(6) + bonus;
}

Finally we have result, which is mystery4 with 2 as its parameter:

var result = jumble(2);

return mystery2(6) + 2;

And to get the final result, we pass 6 as a parameter to mystery2:

function mystery2(6) {
  multiplier = 6 * 5; // 30
  return 4 * 30; // 120
}

result is therefore 120 + 2 = 122