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object

pick

Creates a new object composed of the picked object properties. Extracts only the specified keys from the source object, creating a new object with just those properties. Non-existent keys are silently ignored.

Installation

npx fragmen add object/pick

Source Code

/**
 * Creates a new object composed of the picked object properties.
 *
 * Extracts only the specified keys from the source object, creating a new object
 * with just those properties. Non-existent keys are silently ignored.
 *
 * @tags pure, object-manipulation
 * @param {T} obj The source object to pick properties from.
 * @param {K[]} keys Array of property names to pick from the source object.
 * @returns {Pick<T, K>} A new object containing only the specified properties.
 *
 * @example
 * ```typescript
 * const user = { id: 1, name: 'John', email: 'john@example.com', age: 30 };
 * const publicInfo = pick(user, ['id', 'name']);
 * // Result: { id: 1, name: 'John' }
 *
 * const nonExistent = pick(user, ['id', 'role']); // 'role' doesn't exist
 * // Result: { id: 1 }
 * ```
 */
export function pick<T extends object, K extends keyof T>(
  obj: T,
  keys: K[]
): Pick<T, K> {
  const result = {} as Pick<T, K>;

  for (const key of keys) {
    if (key in obj) {
      result[key] = obj[key];
    }
  }

  return result;
}

Examples

const user = { id: 1, name: 'John', email: 'john@example.com', age: 30 };
const publicInfo = pick(user, ['id', 'name']);
// Result: { id: 1, name: 'John' }

const nonExistent = pick(user, ['id', 'role']); // 'role' doesn't exist
// Result: { id: 1 }

Related Utilities

clone

object

Creates a deep copy of an object. Recursively clones all properties of an object, including nested objects and arrays. Handles circular references by maintaining a reference map. Primitive values, functions, and built-in objects like Date and RegExp are handled appropriately.

#pure#object-manipulation

omit

object

Creates a new object by omitting specified keys from the source object. Returns a new object that contains all properties from the source object except for the specified keys. This is the opposite of the pick utility. The operation is shallow - nested objects are not deeply omitted.

#pure#object-manipulation

has-path

object

Checks if a nested property path exists in an object. Safely traverses nested object properties using a dot-notation path string or an array of keys. Returns true if the path exists (even if the final value is undefined), false if any part of the path is missing.

#pure#validation

deep-equal

object

Performs deep equality comparison between two values

merge

object

Checks if a value is a non-array, non-null object.

chunk

array

Splits an array into chunks of a specified size. Creates a new array containing subarrays (chunks) of the original array, each with a maximum length of the specified size. The last chunk may contain fewer elements if the array length is not evenly divisible by the chunk size.

#pure#array-manipulation

Quick Actions

Estimated size:1.01 KB

Tags

#pure#object-manipulation

Parameters

objT

The source object to pick properties from.

keysK[]

Array of property names to pick from the source object.

Returns

Pick<T, K>

A new object containing only the specified properties.