# Chapter 14. Metaprogramming

## 14.1 Property Attributes

## 14.2 Object Extensibility

## 14.3 The prototype Attribute

## 14.4 Well-Known Symbols

### 14.4.1 Symbol.iterator and Symbol.asyncIterator

### 14.4.2 Symbol.hasInstance

### 14.4.3 Symbol.toStringTag

### 14.4.4 Symbol.species

### 14.4.5 Symbol.isConcatSpreadable

### 14.4.6 Pattern-Matching Symbols

### 14.4.7 Symbol.toPrimitive

### 14.4.8 Symbol.unscopables

## 14.5 Template Tags

## 14.6 The Reflect API

## 14.7 Proxy Objects

### 14.7.1 Proxy Invariants