Reflect.apply()

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

Try it

console.log(Reflect.apply(Math.floor, undefined, [1.75]));
// Expected output: 1

console.log(
  Reflect.apply(String.fromCharCode, undefined, [104, 101, 108, 108, 111]),
);
// Expected output: "hello"

console.log(
  Reflect.apply(RegExp.prototype.exec, /ab/, ["confabulation"]).index,
);
// Expected output: 4

console.log(Reflect.apply("".charAt, "ponies", [3]));
// Expected output: "i"

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

TypeError: Thrown if target is not a function or argumentsList is not an object.

Description

Reflect.apply() provides the reflective semantic of a function call. That is, Reflect.apply(target, thisArgument, argumentsList) is semantically equivalent to:

Math.floor.apply(null, [1.75]);
Reflect.apply(Math.floor, null, [1.75]);

The only differences are:

Reflect.apply() takes the function to call as the target parameter instead of the this context.
Reflect.apply() throws if argumentsList is omitted instead of defaulting to calling with no parameters.

Reflect.apply() invokes the [[Call]] object internal method of target.

Examples

undefined

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

ECMAScript® 2027 Language Specification