wealthfront-js-prep.js

// JavaScript variables belong to one of the following scopes: global or local(function). 
// Basically, any variable defined outside of a function is a global variable. Variables 
// defined inside of a function are scoped narrowly to that function, and any other 
// functions defined within the scope of that function (explicit use of the var keyword assumed).

var myName = "john";

var capitalizeMyName = function() {
  myName = myName.substring(0).toUpperCase() + myName.slice(1);
  var name = myName;
}

capitalizeMyName();
console.log(myName);
console.log(name);

// What will happen to the myName variable? Why? What is expected value should console.log(name) return?

// The myName variable will be assigned the value "John" when capitalizeMyName() is called,
// because inside the function we are referencing the global variable myName. The value console.log(name) 
// should return undefined, because in name variable doesn't exist in the global scope.

// This answer shows that the candidate understands how JavaScript handles scope.

var palindromeChecker = function(word) {
  for(var i=0, j=word.length-1; i < j; i++, j--) {
    if(word.charAt(i) !== word.charAt(j)) {
      return false;
    }
  }
  return true;
}

var palindromeCheckerRecursive = function(word) {
  if(word.length <= 1) {
    return true;
  } else {
    if(word.charAt(0) === word.charAt(word.length - 1)) {
      return palindromeCheckerRecursive(word.substring(1, word.length - 1));
    } else {
      return false;
    }
  }
}

var Person = function(firstName, lastName) {
  this.firstName = firstName;
  this.lastName  = lastName;
}

Person.prototype.fullName = function() {
  return this.firstName + " " + this.lastName;
}