iteratee

INFO

This function is only available in es-toolkit/compat for compatibility reasons. It either has alternative native JavaScript APIs or isn’t fully optimized yet.

When imported from es-toolkit/compat, it behaves exactly like lodash and provides the same functionalities, as detailed here.

Creates a function that returns a value from an element in a collection.

You can call iteratee with the following types of arguments:

• Function: Returns the function as-is, which will be called with the element from the collection.
• Property name: Returns the value of the specified property from the element.
• Property-value pair: Returns a boolean indicating whether the element's property matches the given value.
• Partial object: Returns a boolean indicating whether the element matches the properties of the partial object.

If you don't provide any arguments or pass null, this function will return a function that simply returns its input unchanged.

Signature

function iteratee(value?: null): <T>(value: T) => T;
function iteratee<F extends (...args: any[]) => unknown>(func: F): F;
function iteratee(value: symbol | number | string | object): (...args: any[]) => any;
function iteratee(
  value?: symbol | number | string | object | null | ((...args: any[]) => unknown)
): (...args: any[]) => any;

Parameters

• value (symbol | number | string | object | null | ((...args: any[]) => any)): The value to convert to an iteratee.

Returns

((...args: any[]) => unknown): Returns the new iteratee function.

Examples

const func = iteratee();
[{ a: 1 }, { a: 2 }, { a: 3 }].map(func) // => [{ a: 1 }, { a: 2 }, { a: 3 }]

const func = iteratee((object) => object.a);
[{ a: 1 }, { a: 2 }, { a: 3 }].map(func) // => [1, 2, 3]

const func = iteratee('a');
[{ a: 1 }, { a: 2 }, { a: 3 }].map(func) // => [1, 2, 3]

const func = iteratee({ a: 1 });
[{ a: 1 }, { a: 2 }, { a: 3 }].find(func) // => { a: 1 }

const func = iteratee(['a', 1]);
[{ a: 1 }, { a: 2 }, { a: 3 }].find(func) // => { a: 1 }