Check for string to not be empty?

Not sure why I am struggling with this right now:

            const { gender, firstname, lastname, email, mobile } = recipientData;

            if (
                gender === undefined ||
                gender === null ||
                firstname === undefined ||
                firstname === null ||
                lastname === undefined ||
                lastname === null ||
                ((email === undefined || email === null) &&
                    (mobile === undefined || mobile === null))
            ) {
                throw new ResponseError("missing_data");
            }

            const { gender, firstname, lastname, email, mobile } = recipientData;

            if (
                gender === undefined ||
                gender === null ||
                firstname === undefined ||
                firstname === null ||
                lastname === undefined ||
                lastname === null ||
                ((email === undefined || email === null) &&
                    (mobile === undefined || mobile === null))
            ) {
                throw new ResponseError("missing_data");
            }

Is there a better way of checking if the data is not set, unfortunatly I get the ResponseError if I pass empty strings.

5 Replies

Ebert•12mo ago

Hello, one way to improve your code is check for falsy values using the ! operator For example, instead of checking if theses values are null or undefined like this:

if (
  gender === undefined ||
  gender === null ||
  firstname === undefined ||
  firstname === null ||
  lastname === undefined ||
  lastname === null ||
)

if (
  gender === undefined ||
  gender === null ||
  firstname === undefined ||
  firstname === null ||
  lastname === undefined ||
  lastname === null ||
)

You can check if the value is falsy with the ! operator:

if (
  !gender ||
  !firstname ||
  !lastname
)

if (
  !gender ||
  !firstname ||
  !lastname
)

Have a quick look about checking for falsy values in Javascript on this article: https://www.freecodecamp.org/news/falsy-values-in-javascript/

freeCodeCamp.org

Falsy Values in JavaScript

Description A falsy value is something which evaluates to FALSE, for instance when checking a variable. There are only six falsey values in JavaScript: undefined, null, NaN , 0, "" (empty string), and false of course. Checking for falsy values on variables It is possible to check for a falsy

Ebert•12mo ago

If you want to allow empty strings to pass on this verification you can use a logic like that:

if (
  !gender && gender !== "" ||
  !firstname && firstname !== ""||
  !lastname && lastname !== ""
....
)

if (
  !gender && gender !== "" ||
  !firstname && firstname !== ""||
  !lastname && lastname !== ""
....
)

Josh•12mo ago

use a zod validator

Josh•12mo ago

https://zod.dev/

GitHub

TypeScript-first schema validation with static type inference

JUNGLEJIMBO•12mo ago

big +1 for zod. colocating your types and validation feels like magic

Gaming

Programming

Check for string to not be empty?