How to handle any as parameter type in TypeScript?

Question

I want to use this generic helper function to create form data:

function createFormData(data: any): FormData {
  const formData = new FormData();

  for (const key in data) {
    formData.append(key, data[key]);
  }

  return formData;
}

But the ESLint gives me an unexpected any warning. When I change the parameter type any to object it shows me the following error message for data[key]:

Element implicitly has an 'any' type because expression of type 'string' can't be used to index type '{}'. No index signature with a parameter of type 'string' was found on type '{}'

How can I fix my code here in order that no error messages or warnings are shown (without just turning off the linter)?

Duplicate of [Element implicitly has an 'any' type because expression of type 'string' can't be used to index](https://stackoverflow.com/questions/57086672/element-implicitly-has-an-any-type-because-expression-of-type-string-cant-b) — Guy Incognito, Oct 11 '20 at 15:55
@GuyIncognito I don't think it's a duplicate. I'm asking explicitly for function parameter handling and how to surpress the ESLint warning for the usage of any — winklerrr, Oct 11 '20 at 17:23

score 0 · Answer 1 · answered Oct 11 '20 at 15:55

0

Instead of any you could provide the value data type also

function createFormData(data: {[key: string]: any}): FormData {
  const formData = new FormData();

  for (const key in data) {
    formData.append(key, data[key]);
  }

  return formData;
}

answered Oct 11 '20 at 15:55

Alok Takshak

282
1
6

The ESLint warning `unexpected any` is still shown – winklerrr Oct 11 '20 at 17:22
https://codesandbox.io/s/cranky-grass-olpe8 – Alok Takshak Oct 11 '20 at 18:05
So you are telling me, because they did it in that example project, it's the right way to go? – winklerrr Oct 11 '20 at 19:10
This is what i have created, also i think you need to define type for you data and if it throws error for using key as a string you might have to add the type of keys as string – Alok Takshak Oct 12 '20 at 02:47
The `key: string` part is fine. But it shows a warning because of the `any` keyword. – winklerrr Oct 12 '20 at 08:28
for that you you can provide the type i suppose for you it would be sting only {[key: string] :string} – Alok Takshak Oct 12 '20 at 09:15
But let's say I want to override the `console.log` function which takes `...data: any`. How can I achieve that? – winklerrr Oct 12 '20 at 09:21

How to handle any as parameter type in TypeScript?

1 Answers1