Using Objects for Lookups it does not work

JavaScript
1

What am I doing wrong ? I have seen many examples and I do not see how to understand Using Objects for Lookups.
Objects can be considered as key / value storage, like a dictionary. If you have tabular data, you can use an object to “search” for values instead of a statement switch or an if / elsechain. This is most useful when you know that your input data is limited to a certain range.
Can you help me understand it? My code does not work …
Instructions

Convert the switch statement into a lookup table called lookup. Use it to lookup val and assign the associated string to the result variable.

// Setup
function phoneticLookup(val) {
  var result = "";

  // Only change code below this line
  var lookup= {

      alpha:"Adams",

      bravo: "Boston",
 
      charlie: "Chicago",

      delta:"Denver",
  
     eco: "Easy",
 
      "foxtrot": "Frank",
    result : lookup[val]
  };

  // Only change code above this line
  return result;
}

// Change this value to test
phoneticLookup("charlie");

VM216:19 Uncaught TypeError: Cannot read property 'charlie' of undefined
    at phoneticLookup (<anonymous>:19:20)
    at <anonymous>:27:1
1 Like
2

Hey @miguelito! You almost there, I’ll give you a small suggestion here.
Look closely at your lookup object (you use it as a dictionary here). It has to do just one thing - store the data.
After that, you should assign the value to the variable result. To do that you should use the syntax lookup[val] as you do, but it shouldn’t be in the object, it’ll be different operation.
Please try to separate them and if you have further questions, feel free to tag me out.

1 Like
3

I’ve edited your post for readability. When you enter a code block into the forum, precede it with a line of three backticks and follow it with a line of three backticks to make easier to read. See this post to find the backtick on your keyboard. The “preformatted text” tool in the editor (</>) will also add backticks around text.

markdown_Forums

2 Likes
4

I still do not understand.
Change result, but it does not work I do not understand it.
result : val.lookup

5

Thank you for the support and understanding.
I should check before the link that you propose and learn more about the site.

6

You was trying to do that inside the object. You cannot assign variable inside the object. You should try to do that outside of the curly braces

1 Like
7 
function phoneticLookup(val) {
  var result = "";

  // Only change code below this line
  var lookup= {

      "alpha":"Adams",

      "bravo": "Boston",
 
      "charlie": "Chicago",

      "delta":"Denver",
  
     "eco": "Easy",
 
      "foxtrot": "Frank",
    
  };
  
 result = val.lookup;

  // Only change code above this line
  return result;
}

// Change this value to test
phoneticLookup("charlie"); ```

It does not work, I do not understand
8

What’s the reason did you change lookup[val] on val.lookup;?
lookup[val] was correct syntax.

1 Like
9

You are right, I’m wrong. But it still fails, it must return:
phoneticLookup(“echo”) should equal “Easy”.
It is the only one that fails

10

function phoneticLookup(val) {
var result = “”;

var lookup= {

  "alpha":"Adams",

  "bravo": "Boston",

  "charlie": "Chicago",

  "delta":"Denver",

 "echo": "Easy",

  "foxtrot": "Frank",

};

result = lookup[val];

return result;
}

phoneticLookup("");

1 Like
11

That’s because you have a typo error in the word echo. Your said eco

12

That was the problem, which would be the programming without the typographical errors … thanks

13

Just detach a little from the code and after you will see the error.

3 Likes