functions (Lodash compatibility)

::: warning Use Object.keys and typeof check

This functions function operates slowly as it internally goes through the keys function and filtering process.

Instead, use the faster and more modern Object.keys and typeof check.

:::

Returns an array of the names of the object's own properties that are functions.

typescript

const functionNames = functions(obj);

Usage

`functions(object)`

Checks the object's own properties and returns an array of only the names of properties that are functions. It excludes inherited properties and Symbol keys, checking only string key properties that the object directly owns. This is useful when finding methods of an object or handling only function properties separately.

typescript

import { functions } from 'es-toolkit/compat';

// Basic usage
const obj = {
  name: 'John',
  age: 30,
  greet: () => 'Hello',
  calculate: function (x, y) {
    return x + y;
  },
};

const functionNames = functions(obj);
// Result: ['greet', 'calculate']

// Finding functions in a class instance
class Calculator {
  constructor() {
    this.value = 0;
    this.add = function (n) {
      this.value += n;
    };
  }

  multiply(n) {
    this.value *= n;
  }
}

Calculator.prototype.divide = function (n) {
  this.value /= n;
};

const calc = new Calculator();
const methods = functions(calc);
// Result: ['add'] (inherited multiply, divide are excluded)

// Object with no functions
const data = { x: 1, y: 2, z: 'text' };
const noFunctions = functions(data);
// Result: []

null or undefined are treated as empty arrays.

typescript

import { functions } from 'es-toolkit/compat';

functions(null); // []
functions(undefined); // []

Parameters

object (any): The object to check.

Returns

(string[]): Returns an array of the names of properties that are functions.