Solving "Make a Person" / freeCodeCamp Algorithm Challenges

#freecodecamp #algorithms #challenge #javascript

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Let's solve freeCodeCamp's intermediate algorithm scripting challenge, 'Make a Person'.

Starter Code

var Person = function(firstAndLast) {
  // Only change code below this line
  // Complete the method below and implement the others similarly
  this.getFullName = function() {
    return "";
  };
  return firstAndLast;
};

var bob = new Person('Bob Ross');
bob.getFullName();

Instructions

Fill in the object constructor with the following methods below:

getFirstName()
getLastName()
getFullName()
setFirstName(first)
setLastName(last)
setFullName(firstAndLast)

Run the tests to see the expected output for each method. The methods that take an argument must accept only one argument and it has to be a string. These methods must be the only available means of interacting with the object.

Test Cases

Object.keys(bob).length should return 6.
bob instanceof Person should return true.
bob.firstName should return undefined.
bob.lastName should return undefined.
bob.getFirstName() should return "Bob".
bob.getLastName() should return "Ross".
bob.getFullName() should return "Bob Ross".
bob.getFullName() should return "Haskell Ross" after bob.setFirstName("Haskell").
bob.getFullName() should return "Haskell Curry" after bob.setLastName("Curry").
bob.getFullName() should return "Haskell Curry" after bob.setFullName("Haskell Curry").
bob.getFirstName() should return "Haskell" after bob.setFullName("Haskell Curry").
bob.getLastName() should return "Curry" after bob.setFullName("Haskell Curry").

Our Approach

The instructions for this challenge are short and to the point.

We're working with a function expression, with an argument of firstAndLast.
It is an object constructor that we need to complete. The instructions mention methods which must be included in the object constructor.

This challenge is a little unique as we have to build out and complete an object constructor. freeCodeCamp provided a few lessons about object constructors from what I remember so it may be helpful to go back and look at them.

The instructions let us know which methods have to be created, so let's get down to it.

The argument for this constructor is firstAndLast, which will be a string of a first and last name, separated by a white space (according to our test cases). I think it will be handy to separate out the first and last name into their own variables as some methods require us to return either name. We can deconstruct the argument as seen below.

let [firstName, lastName] = firstAndLast.split(' ');
// We're splitting on the white space between the two names

var Person = function(firstAndLast) {
    let [firstName, lastName] = firstAndLast.split(' ');
    console.log(firstName, lastName)
};

Person('Bob World') // Bob, World

Okay, we won't need the console.log() in our solution but we're off to a good start.

Before we dive into approaching each method, I found this to be good documentation about constructor functions.

JavaScript.info - Constructor, operator "new"

getFirstName()

This method, as it states, will return the first name. We have that in a variable already. So our code would look something like this:

this.getFirstName = function() {
  return firstName;
}

Our next method will be getLastName() will be the pretty much the same.

this.getLastName = function() {
  return lastName;
}

Let's skip over getFullName() for now. The reason is it will have to be updated if we run a 'set' method to change the name.

For setFirstName(), we'll have it take in an argument, and then update the firstName variable to the new one provided in this function.

this.setFirstName = function (first) {
  firstName = first;
  return firstName;
}

setLastName() will work very similarly.

this.setLastName = function (last) {
  lastName = last;
  return lastName;
}

The most challenging method is setFullName(). We will have to replace both variables with the new argument provided in this function. Like the argument of the constructor function, we assume (based off the test cases), it will be a string with a first and last name, separated by a white space.

this.setFullName = function (firstAndLast) {
  firstName = firstAndLast.split(' ')[0];
  lastName = firstAndLast.split(' ')[1];
  return `${firstName} ${lastName}`;
}

MDN: String.split()

We take the argument, split it at the white space, and then set each string into the firstName and lastName variables.

Returning to the last method we didnt cover, getFullName().

this.getFullName = function () {
    return `${firstName} ${lastName}`;
};

Our Solution

var Person = function(firstAndLast) {
  // Complete the method below and implement the others similarly

  let [firstName, lastName] = firstAndLast.split(' ');

  this.getFirstName = function() {
    return firstName;
  };

  this.getLastName = function() {
    return lastName;
  };

  this.getFullName = function() {
    return `${firstName} ${lastName}`;
  };

  this.setFirstName = function(first) {
    firstName = first;
    return firstName;
  };

  this.setLastName = function(last) {
    lastName = last;
    return lastName;
  }

  this.setFullName = function(firstAndLast) {
    firstName = firstAndLast.split(' ')[0];
    lastName = firstAndLast.split(' ')[1];
    return `${firstName} ${lastName}`;
  }

};