Reflect.apply() - JavaScript 编辑

The static Reflect.apply() method calls a target function with arguments as specified.

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The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

Syntax

Reflect.apply(target, thisArgument, argumentsList)

Parameters

target

The target function to call.

thisArgument

The value of this provided for the call to target.

argumentsList

An array-like object specifying the arguments with which target should be called.

Return value

The result of calling the given target function with the specified this value and arguments.

Exceptions

A TypeError, if the target is not callable.

Description

In ES5, you typically use the Function.prototype.apply() method to call a function with a given this value and arguments provided as an array (or an array-like object).

Function.prototype.apply.call(Math.floor, undefined, [1.75]);

With Reflect.apply() this becomes less verbose and easier to understand.

Examples

Using Reflect.apply()

Reflect.apply(Math.floor, undefined, [1.75]);
// 1;

Reflect.apply(String.fromCharCode, undefined, [104, 101, 108, 108, 111])
// "hello"

Reflect.apply(RegExp.prototype.exec, /ab/, ['confabulation']).index
// 4

Reflect.apply(''.charAt, 'ponies', [3])
// "i"

Specifications

Specification
ECMAScript (ECMA-262) The definition of 'Reflect.apply' in that specification.

Browser compatibility

BCD tables only load in the browser

See also

• Reflect
• Function.prototype.apply()