I have two routes, /Profile which shows the user their own profile. (it doesnt need to request this because their profile is already stored in state)

Then the second /Profile/.... which shows the user other profiles. (it does need to request this because the state does not store all other users)

To have this functionality I have tried inputting this undefined / null check but it doesn't fail when the params are empty:

  const getRequest = async () => {
    const user_response = null;
    console.log("param",params)
    console.log("param id",params.id)

    if (params !== null || params !== undefined) {
      console.log("params true")

      if (params.id !== null || params.id !== undefined) {
        console.log("id true")
      }
      else{
        console.log("false")
      }
    }
    else{
       console.log("false")
    }

The following is the console outputs when no params are passed:

> param {}
> param id undefined
> params true
> id true

The following is the console outputs when params are passed:

> param {id: '321'}
> param id 321
> params true
> id true

How can I make it work as intended?

CodePudding user response：

If your user ID can't be falsy (e.g. 0 is not a valid user ID, or '' isn't), then just

const userId = params?.id || null;

without any other fuss – userId it'll be either the ID if it's truthy, or null.

CodePudding user response：

the empty object still return true, so if you want to check the object is empty or not you must do something like this:

const obj = {};
const isEmpty = Object.keys(obj).length === 0;

then you can check the param object with this

CodePudding user response：

It looks like when you're not passing any params, "params" is default an empty object which is bypassing your if statementes ( because it is actually different than null and undefined) You need a more clear condition; can use lodash library which has a method _.isEmpty() to check for empty objects or as other have stated use the Object.Keys length