I am unsuccessfully trying to initialise and use a service class from a React hook. The service class looks like:

export class ExampleService {
  constructor(private exampleParams: string[]) {}

  isPresent(exampleName: string): boolean {
    return this.exampleParams.includes(exampleName);
  }

  getAll(): string[] {
    return this.exampleParams;
  }

  setExamples(exampleParams: string[]): void {
    this.exampleParams = exampleParams;
  }
}

And then in the hook I am trying to use this class:

import { ExampleService } from '../somewhere/example-service';
import { useContext } from 'react';

import { ExampleContext } from '../contexts/example-context';

export const useExample = () => {
  const { currentExamples } = useContext(ExampleContext);
  const checkExamples = new ExampleService(currentExamples);

  return [checkExamples.isPresent];
};

However, I am getting TypeError: Cannot read property 'exampleParams' of undefined when I try to test the code :/ (The error is on isPresent function above).

What am I doing wrong?