将javascript列表转换为字典

Question

I'm trying to convert a javascript list to a dictionary with a specified key. I'm using the following code:

 let list = ['cat', 'rabbit', 'fish'] list = list.map(x => { return ({ animal: x }); }) console.log(list); 

Of course this doesn't work. Edit: It actually does

Expected result:

[
  {
    "animal": "cat"
  },
  {
    "animal": "rabbit"
  },
  {
    "animal": "fish"
  }
]

Edit:

let and list=list was in fact a typo in the question - it is correct in my real code. I didnt test this snippet as I didnt think it worked. I also then confused myself and did type the expected result wrong. My code is more complex and it didn't make sense to post it all. As works, I think my bug must be elsewhere. Thanks for the help.

Answer 1

Of course this doesn't work.

It does (if we fix the typo in Let and we assume you wanted an array of three objects), you're just not using the result:

  let list = ['cat', 'rabbit', 'fish'] // vvvvvvv list = list.map(x => { return({animal: x}); }); console.log(list); 

Or more briefly with a concise arrow function:

 let list = ['cat', 'rabbit', 'fish'] list = list.map(x => ({animal: x})); console.log(list); 

Answer 2

I'll make an asside to @TJ Crowder's answer: Ecma Script 6 (ES6) could not render in old browsers and Internet Explorer (just arrow functions => ) you could use code below instead:

 var list = ['cat', 'rabbit', 'fish'] list = list.map(function(x) { return ({ animal: x }); }); console.log(list); 

If you'll keep the original list, you could use code below:

 var list = ['cat', 'rabbit', 'fish'] var result = list.map(function(x) { return ({ animal: x }); }); console.log(list); console.log(result); 

Typical things in ES6 are:

• let and const keywords | check: caniuse.com
• Arrow functions ( => ) | check: caniuse.com