Javascript ignore object if no data-CodePudding

I'm pulling the types of a Pokémon from the pokeAPI for my discord.js command. It's working fine if a Pokémon has two types, but I'm having an issue when a Pokémon has only one type.

I define them in my file:

const type1 = types[0].type.name;
const type2 = types[1].type.name;

And load them in my embed:

{
name: "Type",
value: `${type1}, ${type2}`,
inline: false,
},

The API data:

One Type

  "types": [
    {
      "slot": 1,
      "type": {
        "name": "normal",
        "url": "https://pokeapi.co/api/v2/type/1/"
      }
    }
  ],

Two Types

  "types": [
    {
      "slot": 1,
      "type": {
        "name": "poison",
        "url": "https://pokeapi.co/api/v2/type/4/"
      }
    },
    {
      "slot": 2,
      "type": {
        "name": "flying",
        "url": "https://pokeapi.co/api/v2/type/3/"
      }
    }
  ],

When I try to run my command with a Pokémon with one type, I get the following error in the console: TypeError: Cannot read properties of undefined (reading 'type')

I figure I've got to do something in the embed to ignore the second type if it isn't there, but I can't figure it out. I tried the following also, but the api is not returning anything, even null:

`${type1}, ${type2 == null ? `` : `${type2}`}`

Someone who can help me on the right track?

CodePudding user response：

It seems that the second item in the array (index 1) is missing in that case. So you need to check if the array is long enough.

const type2 = types.length>1 ? types[1].type.name : null;

CodePudding user response：

At its core, the issue is that the array can be any length. I think a better approach here would be something like this:

var typeList = types.map(t => t.name).join(', ');

This will produce the comma-separated listing without concerning yourself with its length.

Then you can build the object like this:

{
  name: "Type",
  value: typeList,
  inline: false,
}

CodePudding user response：

If you're using ES6, you could use nullish coalescing operator to shorten up your code.

Eg:

const type2 = type[1]?.type?.name ?? null;