Accessing Objects Properties with Variables

JavaScript
1

Tell us what’s happening:

Your code so far

// Setup
var testObj = {
  12: "Namath",
  16: "Montana",
  19: "Unitas"
};

// Only change code below this line;

var playerNumber = testObj[16];       // Change this Line
var player = "Montana";   // Change this Line

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36.

Link to the challenge:
https://www.freecodecamp.org/challenges/accessing-objects-properties-with-variables

2

Do you have a question?

3

yes
i used bracket notation in playerNumber with number. eventhough it throwing me a error.

4

Read the instructions carefully. You are not currently using a variable to access an object property.

5

Thank you. i got it.

6

How did you get it because i only need the last area and seem to be getting it here is my code:

var playerNumber // Change this Line
var player = testObj[“16”]; // Change this Line

7

You didn’t declare playerNumber with a value and you didn’t use it anywhere.
"16" is not the number 16, but the string of characters “16”. Also, you shouldn’t be hardcoding a value there at all because the challenge is “Accessing Object Properties with Variables”.

1 Like
8

okay thanks ive got it

9

Guys, I still have a question about this one.
There are 2 goals of the exercise as I understand it:

  1. Use the playerNumber variable to look up player 16 in testObj using bracket notation.
  2. Then assign that name to the player variable.

And then if you look into solution:

var playerNumber = 16;       // I do not see any bracket notation during this look up. Am I missing something?
var player = testObj[playerNumber];   // this one is clear

While reading the task I was going for that solution (but obviously it didn’t worked):

var playerNumber = testObj[16];       
var player = playerNumber;

Here’s the question (if you’ve missed it in the comment above) - I do not see any playerNumber variable look up in testObj using bracket notation

Most likely I’m not getting a task properly or there’s a chance that task is incorrectly formulated?

10

When it says “use the playerNumber variable… Using bracket notation” it means that the variable should be used in the lookup expression. What you have would probably br phrased something like “use bracket notation to assign a value to playerNumber”. The point of this exercise is to show you that when you are using a variable to lookup an object property, you need to use bracket notation.

11

Thank you Ariel!
I somehow focused on bracket notation and haven’t interpreted it as lookup expression.

12

I’m glad I could help. Happy coding!