Help with the Profile Lookup? [SOLVED][SPOILERS]

#1

I figured out that the hasOwnProperty function would do the trick, but i don’t know what’s happening.
> var contacts = [

{
    "firstName": "Akira",
    "lastName": "Laine",
    "number": "0543236543",
    "likes": ["Pizza", "Coding", "Brownie Points"]
},
{
    "firstName": "Harry",
    "lastName": "Potter",
    "number": "0994372684",
    "likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
    "firstName": "Sherlock",
    "lastName": "Holmes",
    "number": "0487345643",
    "likes": ["Intriguing Cases", "Violin"]
},
{
    "firstName": "Kristian",
    "lastName": "Vos",
    "number": "unknown",
    "likes": ["Javascript", "Gaming", "Foxes"]
}

];

function lookUpProfile(firstName, prop){

return contacts.hasOwnProperty(firstName);
}

lookUpProfile(“Akira”, “likes”);

Why does
"return contacts.hasOwnProperty(firstName);" return false?

#2

A few things.

contacts is an array, not an object so it won’t have a property.

Inside your function firstName is an argument variable. This means that in the case of lookUpProfile("Akira", "likes"), the variable firstName is "Akira" so contacts.hasOwnProperty(firstName) is the same as contacts.hasOwnProperty("Akira").

#3

Okay, that I knew.
So I would need to iterate through the array so I can check every object?
Maybe something like

for (var i = 0; i < contacts.length; i++) {

if (contacts[i].hasOwnProperty) {
do something here
}
}

Am I on the right track?

#4

That’s a step in the right direction. Keep in mind though that none of the objects in the array will have the property "Akira", so it will still be false.

#5

Ah, so this was the problem
How can I access the left-part? The ones that’s not the property, was it called key?

#6

“key” and “property” mean the same thing in this context. That’s the “left-hand side”. The “right-hand side” is referred to as the “value” or sometimes “contents”.

#7

Okay, so, I think this should do the trick.

function lookUpProfile(firstName, prop){
  for (var i = 0; i < contacts.length; i++) {
    if (firstName == contacts[0].firstName) {
      return true;
    }
  }
}
#8

Looks like you’re on the right track. :thumbsup:

#9

Okay, so, I’m nearly there:

function lookUpProfile(firstName, prop){
  for (var i = 0; i < contacts.length; i++) {
    if (firstName == contacts[i].firstName) {
      return contacts[i][prop];
    }
  }
}

However, I still have a problem with the function returning “No such contact/property”, because i can’t just do:

function lookUpProfile(firstName, prop){
      for (var i = 0; i < contacts.length; i++) {
        if (firstName == contacts[i].firstName) {
          return contacts[i][prop];
        }
        else {
          return "No such contact"
       }
      }
    }

Since this will break the function before i is able to add one to itself.

Any help would be appreciated

#10

If you have already looped through all of contacts without returning a value, then you know that there was no contact with a matching firstName. The “No such property” bit is when you’d want to use hasOwnProperty().

#11

So, this almost works:

function lookUpProfile(firstName, prop){
  for (var i = 0; i < contacts.length; i++) {
    if (firstName == contacts[i].firstName) {
      if (contacts[i].hasOwnProperty(prop)) {
        return contacts[i][prop];
      }
      else {
        return "No such property";
        }
      }
    }
  }

But the only requirement I have left it’s to return “No such contact” when the contact doesn’t exist, but I don’t know how to achieve that without stopping the [i] iteration.

Also, the code it’s getting hard to read, I hope I’ll learn how to write nicer code on the future

#12

:point_up: :wink: :thumbsup:

#13

Great! Thank you, so thinking about that I realized that

function lookUpProfile(firstName, prop){
  for (var i = 0; i < contacts.length; i++) {
    if (firstName == contacts[i].firstName) {
      if (contacts[i].hasOwnProperty(prop)) {
        return contacts[i][prop];
      }
      else {
        return "No such property";
        }
      }
    }
  return "No such contact";
  }

If the whole loop is done and it didn’t return anything, no firstName exists, so i can just return false.

Thanks! I thought i was over for a moment with this one.

2 Likes
#14

This challenge throws a lot of people through a loop. You’ve got this. Happy coding!

1 Like
#15