close

[Solved] Typescript: Object is possibly ‘undefined’

Hello Guys, How are you all? Hope You all Are Fine. Today I get the following error Typescript: Object is possibly ‘undefined’ in javascript. So Here I am Explain to you all the possible solutions here.

Without wasting your time, Let’s start This Article to Solve This Error.

How To Solve Typescript: Object is possibly ‘undefined’ Error ?

  1. How To Solve Typescript: Object is possibly 'undefined' Error?

    To Solve Typescript: Object is possibly 'undefined' Error There are two ways that I can think of to get rid of the error. The first way I can think of is to use a fallback with the || operator, which would turn. Into this, so if the value is falsy, then use an empty string.

  2. Typescript: Object is possibly 'undefined'

    To Solve Typescript: Object is possibly 'undefined' Error There are two ways that I can think of to get rid of the error. The first way I can think of is to use a fallback with the || operator, which would turn. Into this, so if the value is falsy, then use an empty string.

Solution 1

There are two ways that I can think of to get rid of the error.

The first way I can think of is to use a fallback with the || operator, which would turn

a[k].toString().toLowerCase()

Into this, so if the value is falsy, then use an empty string.

(a[k] || '').toString().toLowerCase()
// Or with optional chaining
a[k]?.toString().toLowerCase() || ''

The other way is to save the value to a variable and check the new variable. Which then makes this

if (a && a[k]) {
  return textMatch(txt.toLowerCase(), a[k].toString().toLowerCase()) ? a : null;
}

Become this:

let v = a ? a[k] : null
if (v) {
  return textMatch(txt.toLowerCase(), v.toString().toLowerCase()) ? a : null;
}

Solution 2

Typescript doesn’t keep type information about values at specific array indices. For example, this is an error:

function test(a: (number | string)[]) {
    if (typeof a[3] === "number") {
        const num: number = a[3];
    }
}

To get something that can have type information, you could put a[k] into some other variable like this:

const checkText = (k: string, a: IAsset | null) => {
if (a) {
  const atK = a[k];
  if (atK) {
    return (textMatch(txt.toLowerCase(), atK.toString().toLowerCase()) ? a : null);
  }
}

or you could cast it, because you know more about the types than the type system:

const checkText = (k: string, a: IAsset | null) => {
  if (a && a[k]) {
    return (textMatch(txt.toLowerCase(), (a[k] as string | number | true).toString().toLowerCase()) ? a : null);
  }
}

or you could avoid having to worry about undefineds by using string interpolation:

const checkText = (k: string, a: IAsset | null) => {
  if (a && a[k]) {
    return (textMatch(txt.toLowerCase(), `${a[k]}`.toLowerCase()) ? a : null);
  }
}

Ideally the type system would take care of these things, but I’m sure there’s some reason why this kind of type information isn’t available in general.

Summery

It’s all About this issue. Hope all solution helped you a lot. Comment below Your thoughts and your queries. Also, Comment below which solution worked for you? Thank You.

Also, Read

Leave a Comment