how to use the omitby function from the lodash library in typescript

To use the omitBy function from the Lodash library in TypeScript, first we need to install the @types/lodash package to get type annotations for Lodash functions.

To install the package, run the following command in your terminal:

index.ts
npm install --save-dev @types/lodash
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Once the package is installed, you can import the omitBy function from Lodash:

index.ts
import { omitBy } from "lodash";
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The omitBy function takes two arguments: the object to operate on, and a predicate function that returns true for keys that should be omitted. The predicate function takes two arguments: the value of the current property, and the key of the current property.

Here's an example usage of omitBy in TypeScript:

index.ts
interface User {
  firstName: string;
  lastName: string;
  age: number;
  email: string;
}

const user: User = {
  firstName: "John",
  lastName: "Doe",
  age: 30,
  email: "john.doe@example.com",
};

// Omit all properties with keys that start with "a"
const omittedUser = omitBy(user, (_value, key) => key.startsWith("a"));

console.log(omittedUser);
// Output: { firstName: 'John', lastName: 'Doe', email: 'john.doe@example.com' }
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In this example, we define an interface User that describes the shape of our user data. We create an object user that conforms to this interface.

We then use omitBy to omit all properties from user where the key starts with the letter "a". The result is a new object omittedUser that only contains the firstName, lastName, and email properties.