CODEWITHSUNDEEP
reactjses6-modules
user7087799
user7087799

Reputation: 71

Reactjs not recognize some of the ES6 function?

I am new in Reactjs, I tried to use ES6 code in my React.js file like the following, the compiler not recognized filter and includes?

Error :

    Uncaught TypeError: Cannot read properties of 
    undefined(reading 'filter')...

    const noStoreName = csvFile.filter( e => categoriesFile.includes(e))

Thanks!

Upvotes: 0

Views: 29

Answers (2)

Ali Sattarzadeh
Ali Sattarzadeh

Reputation: 3559

It seems that it's not from compiler

cvsFile is probebly undefiend

so simply add question mark or set if condition

const noStoreName = csvFile?.filter( e => categoriesFile.includes(e))

or :

if(csvFile){
  const noStoreName = csvFile.filter( e => categoriesFile.includes(e))
}

Upvotes: 2

Priyen Mehta
Priyen Mehta

Reputation: 1187

This is not ES6 issue, it is happening because of your csvFile array is empty or undefined in initial, you can do like this:

const noStoreName = csvFile && csvFile.length > 0 && csvFile.filter(e => categoriesFile.includes(e))

If you want to use optional chaining then like this:

const noStoreName = csvFile?.filter( e => categoriesFile?.includes(e))

Upvotes: 1

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