正则表达式

Regular expressions are patterns used to match character combinations in strings. In JavaScript, regular expressions are also objects. These patterns are used with the exec() and test() methods of RegExp , and with the match() , matchAll() , replace() , replaceAll() , search() ,和 split() methods of String . This chapter describes JavaScript regular expressions.

Creating a regular expression

You construct a regular expression in one of two ways:

Writing a regular expression pattern

A regular expression pattern is composed of simple characters, such as /abc/ , or a combination of simple and special characters, such as /ab*c/ or /Chapter (\d+)\.\d*/ . The last example includes parentheses, which are used as a memory device. The match made with this part of the pattern is remembered for later use, as described in Using groups .

注意: If you are already familiar with the forms of a regular expression, you may also read the cheatsheet for a quick lookup for a specific pattern/construct.

Using simple patterns

Simple patterns are constructed of characters for which you want to find a direct match. For example, the pattern /abc/ matches character combinations in strings only when the exact sequence "abc" occurs (all characters together and in that order). Such a match would succeed in the strings "Hi, do you know your abc's?" and "The latest airplane designs evolved from slabcraft." In both cases the match is with the substring "abc" . There is no match in the string "Grab crab" because while it contains the substring "ab c" , it does not contain the exact substring "abc" .

Using special characters

When the search for a match requires something more than a direct match, such as finding one or more b's, or finding white space, you can include special characters in the pattern. For example, to match a single "a" followed by zero or more "b" s followed by "c" , you'd use the pattern /ab*c/ : the * after "b" means "0 or more occurrences of the preceding item." In the string "cbbabbbbcdebc" , this pattern will match the substring "abbbbc" .

The following pages provide lists of the different special characters that fit into each category, along with descriptions and examples.

断言
Assertions include boundaries, which indicate the beginnings and endings of lines and words, and other patterns indicating in some way that a match is possible (including look-ahead, look-behind, and conditional expressions).
Character classes
Distinguish different types of characters. For example, distinguishing between letters and digits.
Groups and ranges
Indicate groups and ranges of expression characters.
量词
Indicate numbers of characters or expressions to match.
Unicode property escapes
Distinguish based on unicode character properties, for example, upper- and lower-case letters, math symbols, and punctuation.

If you want to look at all the special characters that can be used in regular expressions in a single table, see the following:

Special characters in regular expressions.
Characters / constructs Corresponding article
\ , . , \cX , \d , \D , \f , \n , \r , \s , \S , \t , \v , \w , \W , \0 , \xhh , \uhhhh , \uhhhhh , [\b]

Character classes

^ , $ , x(?=y) , x(?!y) , (?<=y)x , (?<!y)x , \b , \B

断言

(x) , (?:x) , (?<Name>x) , x|y , [xyz] , [^xyz] , \ Number

Groups and ranges

* , + , ? , x{ n } , x{ n ,} , x{ n , m }

量词

\p{ UnicodeProperty } , \P{ UnicodeProperty } Unicode property escapes

注意: A larger cheatsheet is also available (only aggregating parts of those individual articles).

Escaping

If you need to use any of the special characters literally (actually searching for a "*" , for instance), you must escape it by putting a backslash in front of it. For instance, to search for "a" followed by "*" followed by "b" , you'd use /a\*b/ — the backslash "escapes" the "*" , making it literal instead of special.

Similarly, if you're writing a regular expression literal and need to match a slash ("/"), you need to escape that (otherwise, it terminates the pattern). For instance, to search for the string "/example/" followed by one or more alphabetic characters, you'd use /\/example\/[a-z]+/i —the backslashes before each slash make them literal.

To match a literal backslash, you need to escape the backslash. For instance, to match the string "C:\" where "C" can be any letter, you'd use /[A-Z]:\\/ — the first backslash escapes the one after it, so the expression searches for a single literal backslash.

If using the RegExp constructor with a string literal, remember that the backslash is an escape in string literals, so to use it in the regular expression, you need to escape it at the string literal level. /a\*b/ and new RegExp("a\\*b") create the same expression, which searches for "a" followed by a literal "*" followed by "b".

If escape strings are not already part of your pattern you can add them using String.replace :

function escapeRegExp(string) {
  return string.replace(/[.*+\-?^${}()|[\]\\]/g, '\\$&'); // $& means the whole matched string
}
				

The "g" after the regular expression is an option or flag that performs a global search, looking in the whole string and returning all matches. It is explained in detail below in Advanced Searching With Flags .

Why isn't this built into JavaScript? There is a proposal to add such a function to RegExp, but it was rejected by TC39.

Using parentheses

Parentheses around any part of the regular expression pattern causes that part of the matched substring to be remembered. Once remembered, the substring can be recalled for other use. See Groups and ranges 了解更多细节。

Using regular expressions in JavaScript

Regular expressions are used with the RegExp methods test() and exec() and with the String methods match() , replace() , search() ,和 split() . These methods are explained in detail in the JavaScript 参考 .

Methods that use regular expressions
Method 描述
exec() Executes a search for a match in a string. It returns an array of information or null on a mismatch.
test() Tests for a match in a string. It returns true or false .
match() Returns an array containing all of the matches, including capturing groups, or null if no match is found.
matchAll() Returns an iterator containing all of the matches, including capturing groups.
search() Tests for a match in a string. It returns the index of the match, or -1 if the search fails.
replace() Executes a search for a match in a string, and replaces the matched substring with a replacement substring.
replaceAll() Executes a search for all matches in a string, and replaces the matched substrings with a replacement substring.
split() Uses a regular expression or a fixed string to break a string into an array of substrings.

When you want to know whether a pattern is found in a string, use the test() or search() methods; for more information (but slower execution) use the exec() or match() methods. If you use exec() or match() and if the match succeeds, these methods return an array and update properties of the associated regular expression object and also of the predefined regular expression object, RegExp . If the match fails, the exec() method returns null (which coerces to false ).

In the following example, the script uses the exec() method to find a match in a string.

var myRe = /d(b+)d/g;
var myArray = myRe.exec('cdbbdbsbz');
				

If you do not need to access the properties of the regular expression, an alternative way of creating myArray is with this script:

var myArray = /d(b+)d/g.exec('cdbbdbsbz');
    // similar to "cdbbdbsbz".match(/d(b+)d/g); however,
    // "cdbbdbsbz".match(/d(b+)d/g) outputs Array [ "dbbd" ], while
    // /d(b+)d/g.exec('cdbbdbsbz') outputs Array [ 'dbbd', 'bb', index: 1, input: 'cdbbdbsbz' ].
				

(见 different behaviors for further info about the different behaviors.)

If you want to construct the regular expression from a string, yet another alternative is this script:

var myRe = new RegExp('d(b+)d', 'g');
var myArray = myRe.exec('cdbbdbsbz');
				

With these scripts, the match succeeds and returns the array and updates the properties shown in the following table.

Results of regular expression execution.
Object Property or index 描述 In this example
myArray The matched string and all remembered substrings. ['dbbd', 'bb', index: 1, input: 'cdbbdbsbz']
index The 0-based index of the match in the input string. 1
input The original string. 'cdbbdbsbz'
[0] The last matched characters. 'dbbd'
myRe lastIndex The index at which to start the next match. (This property is set only if the regular expression uses the g option, described in Advanced Searching With Flags .) 5
source The text of the pattern. Updated at the time that the regular expression is created, not executed. 'd(b+)d'

As shown in the second form of this example, you can use a regular expression created with an object initializer without assigning it to a variable. If you do, however, every occurrence is a new regular expression. For this reason, if you use this form without assigning it to a variable, you cannot subsequently access the properties of that regular expression. For example, assume you have this script:

var myRe = /d(b+)d/g;
var myArray = myRe.exec('cdbbdbsbz');
console.log('The value of lastIndex is ' + myRe.lastIndex);
// "The value of lastIndex is 5"
				

However, if you have this script:

var myArray = /d(b+)d/g.exec('cdbbdbsbz');
console.log('The value of lastIndex is ' + /d(b+)d/g.lastIndex);
// "The value of lastIndex is 0"
				

The occurrences of /d(b+)d/g in the two statements are different regular expression objects and hence have different values for their lastIndex property. If you need to access the properties of a regular expression created with an object initializer, you should first assign it to a variable.

Advanced searching with flags

Regular expressions have six optional flags that allow for functionality like global and case insensitive searching. These flags can be used separately or together in any order, and are included as part of the regular expression.

Regular expression flags
Flag 描述 Corresponding property
g Global search. RegExp.prototype.global
i Case-insensitive search. RegExp.prototype.ignoreCase
m Multi-line search. RegExp.prototype.multiline
s Allows . to match newline characters. RegExp.prototype.dotAll
u "unicode"; treat a pattern as a sequence of unicode code points. RegExp.prototype.unicode
y Perform a "sticky" search that matches starting at the current position in the target string. See sticky . RegExp.prototype.sticky

To include a flag with the regular expression, use this syntax:

var re = /pattern/flags;
				

or

var re = new RegExp('pattern', 'flags');
				

Note that the flags are an integral part of a regular expression. They cannot be added or removed later.

例如, re = /\w+\s/g creates a regular expression that looks for one or more characters followed by a space, and it looks for this combination throughout the string.

var re = /\w+\s/g;
var str = 'fee fi fo fum';
var myArray = str.match(re);
console.log(myArray);
// ["fee ", "fi ", "fo "]
				

You could replace the line:

var re = /\w+\s/g;
				

with:

var re = new RegExp('\\w+\\s', 'g');
				

and get the same result.

The behavior associated with the g flag is different when the .exec() method is used.  The roles of "class" and "argument" get reversed: In the case of .match() , the string class (or data type) owns the method and the regular expression is just an argument, while in the case of .exec() , it is the regular expression that owns the method, with the string being the argument.  Contrast this str.match(re) versus re.exec(str) .  The g flag is used with the .exec() method to get iterative progression.

var xArray; while(xArray = re.exec(str)) console.log(xArray);
// produces:
// ["fee ", index: 0, input: "fee fi fo fum"]
// ["fi ", index: 4, input: "fee fi fo fum"]
// ["fo ", index: 7, input: "fee fi fo fum"]
				

m flag is used to specify that a multiline input string should be treated as multiple lines. If the m flag is used, ^ and $ match at the start or end of any line within the input string instead of the start or end of the entire string.

范例

注意: Several examples are also available in:

Using special characters to verify input

In the following example, the user is expected to enter a phone number. When the user presses the "Check" button, the script checks the validity of the number. If the number is valid (matches the character sequence specified by the regular expression), the script shows a message thanking the user and confirming the number. If the number is invalid, the script informs the user that the phone number is not valid.

Within non-capturing parentheses (?: , the regular expression looks for three numeric characters \d{3} OR | a left parenthesis \( followed by three digits \d{3} , followed by a close parenthesis \) , (end non-capturing parenthesis ) ), followed by one dash, forward slash, or decimal point and when found, remember the character ([-\/\.]) , followed by three digits \d{3} , followed by the remembered match of a dash, forward slash, or decimal point \1 , followed by four digits \d{4} .

Change event activated when the user presses Enter sets the value of RegExp.input .

HTML

<p>
  Enter your phone number (with area code) and then click "Check".
  <br>
  The expected format is like ###-###-####.
</p>
<form action="#">
  <input id="phone">
    <button onclick="testInfo(document.getElementById('phone'));">Check</button>
</form>
				

JavaScript

var re = /(?:\d{3}|\(\d{3}\))([-\/\.])\d{3}\1\d{4}/;
function testInfo(phoneInput) {
  var OK = re.exec(phoneInput.value);
  if (!OK) {
    console.error(phoneInput.value + ' isn\'t a phone number with area code!');
  } else {
    console.log('Thanks, your phone number is ' + OK[0]);}
}
				

结果

工具

RegExr
An online tool to learn, build, & test Regular Expressions.
Regex tester
An online regex builder/debugger
Regex visualizer
An online visual regex tester.

规范

规范
ECMAScript (ECMA-262)
The definition of 'RegExp' in that specification.

浏览器兼容性

更新 GitHub 上的兼容性数据
Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet Node.js
RegExp Chrome 1 Edge 12 Firefox 1 IE 4 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
RegExp() 构造函数 Chrome 1 Edge 12 Firefox 1 IE 4 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
compile
弃用
Chrome 1 Edge 12 Firefox 1 IE 4 Opera 6 Safari 3.1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 2 Samsung Internet Android 1.0 nodejs Yes
dotAll Chrome 62 Edge 79 Firefox 78 IE No Opera 49 Safari 12 WebView Android 62 Chrome Android 62 Firefox Android No Opera Android 46 Safari iOS 12 Samsung Internet Android 8.0 nodejs 8.10.0
8.10.0
8.3.0
Disabled
Disabled From version 8.3.0: this feature is behind the --harmony runtime flag.
exec Chrome 1 Edge 12 Firefox 1 IE 4 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
flags Chrome 49 Edge 79 Firefox 37 IE No Opera 39 Safari 9 WebView Android 49 Chrome Android 49 Firefox Android 37 Opera Android 41 Safari iOS 9 Samsung Internet Android 5.0 nodejs 6.0.0
global Chrome 1 Edge 12 Firefox 1 IE 5.5 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
ignoreCase Chrome 1 Edge 12 Firefox 1 IE 5.5 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
RegExp.input ( $_ )
非标
Chrome 1 Edge 12 Firefox 1 IE 5.5 Opera 15 Safari 3 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 14 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
lastIndex Chrome 1 Edge 12 Firefox 1 IE 5.5 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
RegExp.lastMatch ( $& )
非标
Chrome 1 Edge 12 Firefox 1 IE 5.5 Opera 10.5 Safari 3 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 11 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
RegExp.lastParen ( $+ )
非标
Chrome 1 Edge 12 Firefox 1 IE 5.5 Opera 10.5 Safari 3 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 11 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
RegExp.leftContext ( $` )
非标
Chrome 1 Edge 12 Firefox 1 IE 5.5 Opera 8 Safari 3 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
lookbehind assertions ( (?<= ) and (?<! ) ) Chrome 62 Edge 79 Firefox 78 IE No Opera 49 Safari No WebView Android 62 Chrome Android 62 Firefox Android No
No
bug 1225665 .
Opera Android 46 Safari iOS No Samsung Internet Android 8.0 nodejs 8.10.0
multiline Chrome 1 Edge 12 Firefox 1 IE 5.5 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
RegExp.$1-$9 Chrome 1 Edge 12 Firefox 1 IE 4 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
Named capture groups Chrome 64 Edge 79 Firefox 78 IE No Opera 51 Safari 11.1 WebView Android 64 Chrome Android 64 Firefox Android No Opera Android 47 Safari iOS 11.3 Samsung Internet Android 9.0 nodejs 10.0.0
10.0.0
8.3.0
Disabled
Disabled From version 8.3.0: this feature is behind the --harmony runtime flag.
Unicode property escapes ( \p{...} ) Chrome 64 Edge 79 Firefox 78 IE No Opera 51 Safari 11.1 WebView Android 64 Chrome Android 64 Firefox Android No Opera Android 47 Safari iOS 11.3 Samsung Internet Android 9.0 nodejs 10.0.0
10.0.0
8.3.0
Disabled
Disabled From version 8.3.0: this feature is behind the --harmony runtime flag.
RegExp.rightContext ( $' )
非标
Chrome 1 Edge 12 Firefox 1 IE 5.5 Opera 8 Safari 3 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
source Chrome 1 Edge 12 Firefox 1 IE 4 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
sticky Chrome 49 Edge 13 Firefox 3 IE No Opera 36 Safari 10 WebView Android 49 Chrome Android 49 Firefox Android 4 Opera Android 36 Safari iOS 10 Samsung Internet Android 5.0 nodejs Yes
test Chrome 1 Edge 12 Firefox 1 IE 4 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
toSource
非标
Chrome No Edge No Firefox 1 — 74
1 — 74
Starting in Firefox 74, toSource() is no longer available for use by web content. It is still allowed for internal and privileged code.
IE No Opera No Safari No WebView Android No Chrome Android No Firefox Android 4 Opera Android No Safari iOS No Samsung Internet Android No nodejs No
toString Chrome 1 Edge 12 Firefox 1 IE 4 Opera 5 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs Yes
unicode Chrome 50 Edge 12
12
Case folding is implemented in version 13
Firefox 46 IE No Opera 37 Safari 10 WebView Android 50 Chrome Android 50 Firefox Android 46 Opera Android 37 Safari iOS 10 Samsung Internet Android 5.0 nodejs Yes
@@match Chrome 50 Edge 13 Firefox 49 IE No Opera 37 Safari 10 WebView Android 50 Chrome Android 50 Firefox Android 49 Opera Android 37 Safari iOS 10 Samsung Internet Android 5.0 nodejs 6.0.0
@@matchAll Chrome 73 Edge 79 Firefox 67 IE No Opera 60 Safari 13 WebView Android 73 Chrome Android 73 Firefox Android 67 Opera Android 52 Safari iOS 13 Samsung Internet Android 5.0 nodejs 12.0.0
@@replace Chrome 50 Edge 79 Firefox 49 IE No Opera 37 Safari 10 WebView Android 50 Chrome Android 50 Firefox Android 49 Opera Android 37 Safari iOS 10 Samsung Internet Android 5.0 nodejs 6.0.0
@@search Chrome 50 Edge 13 Firefox 49 IE No Opera 37 Safari 10 WebView Android 50 Chrome Android 50 Firefox Android 49 Opera Android 37 Safari iOS 10 Samsung Internet Android 5.0 nodejs 6.0.0
@@species Chrome 50 Edge 13 Firefox 49 IE No Opera 37 Safari 10 WebView Android 50 Chrome Android 50 Firefox Android 49 Opera Android 37 Safari iOS 10 Samsung Internet Android 5.0 nodejs 6.5.0
6.5.0
6.0.0
Disabled
Disabled From version 6.0.0: this feature is behind the --harmony runtime flag.
@@split Chrome 50 Edge 79 Firefox 49 IE No Opera 37 Safari 10 WebView Android 50 Chrome Android 50 Firefox Android 49 Opera Android 37 Safari iOS 10 Samsung Internet Android 5.0 nodejs 6.0.0

图例

完整支持
完整支持
不支持
不支持
非标。预期跨浏览器支持较差。
弃用。不要用于新网站。
弃用。不要用于新网站。
见实现注意事项。
用户必须明确启用此特征。
用户必须明确启用此特征。
  1. JavaScript
  2. 教程:
  3. 完整初学者
    1. JavaScript 基础
    2. JavaScript 第一步
    3. JavaScript 构建块
    4. 引入 JavaScript 对象
  4. JavaScript 指南
    1. 介绍
    2. 语法和类型
    3. 控制流程和错误处理
    4. 循环和迭代
    5. 函数
    6. 表达式和运算符
    7. 数字和日期
    8. 文本格式
    9. 正则表达式
    10. Indexed collections
    11. Keyed collections
    12. Working with objects
    13. 对象模型的细节
    14. Using promises
    15. 迭代器和生成器
    16. Meta programming
    17. JavaScript 模块
  5. 中间体
    1. Client-side JavaScript frameworks
    2. 客户端侧 Web API
    3. 重新介绍 JavaScript
    4. JavaScript 数据结构
    5. 相等比较和相同
    6. 闭包
  6. 高级
    1. 继承和原型链
    2. 严格模式
    3. JavaScript 类型数组
    4. 内存管理
    5. 并发模型和事件循环
  7. 参考:
  8. 内置对象
    1. AggregateError
    2. Array
    3. ArrayBuffer
    4. AsyncFunction
    5. Atomics
    6. BigInt
    7. BigInt64Array
    8. BigUint64Array
    9. Boolean
    10. DataView
    11. Date
    12. Error
    13. EvalError
    14. FinalizationRegistry
    15. Float32Array
    16. Float64Array
    17. Function
    18. Generator
    19. GeneratorFunction
    20. Infinity
    21. Int16Array
    22. Int32Array
    23. Int8Array
    24. InternalError
    25. Intl
    26. JSON
    27. Map
    28. Math
    29. NaN
    30. Number
    31. Object
    32. Promise
    33. Proxy
    34. RangeError
    35. ReferenceError
    36. Reflect
    37. RegExp
    38. Set
    39. SharedArrayBuffer
    40. String
    41. Symbol
    42. SyntaxError
    43. TypeError
    44. TypedArray
    45. URIError
    46. Uint16Array
    47. Uint32Array
    48. Uint8Array
    49. Uint8ClampedArray
    50. WeakMap
    51. WeakRef
    52. WeakSet
    53. WebAssembly
    54. decodeURI()
    55. decodeURIComponent()
    56. encodeURI()
    57. encodeURIComponent()
    58. escape()
    59. eval()
    60. globalThis
    61. isFinite()
    62. isNaN()
    63. null
    64. parseFloat()
    65. parseInt()
    66. undefined
    67. unescape()
    68. uneval()
  9. 表达式 & 运算符
    1. Addition (+)
    2. Addition assignment (+=)
    3. Assignment (=)
    4. Bitwise AND (&)
    5. Bitwise AND assignment (&=)
    6. Bitwise NOT (~)
    7. Bitwise OR (|)
    8. Bitwise OR assignment (|=)
    9. Bitwise XOR (^)
    10. Bitwise XOR assignment (^=)
    11. Comma operator (,)
    12. 条件 (三元) 运算符
    13. Decrement (--)
    14. Destructuring assignment
    15. Division (/)
    16. Division assignment (/=)
    17. Equality (==)
    18. Exponentiation (**)
    19. Exponentiation assignment (**=)
    20. Function expression
    21. Greater than (>)
    22. Greater than or equal (>=)
    23. Grouping operator ( )
    24. Increment (++)
    25. Inequality (!=)
    26. Left shift (<<)
    27. Left shift assignment (<<=)
    28. Less than (<)
    29. Less than or equal (<=)
    30. Logical AND (&&)
    31. Logical AND assignment (&&=)
    32. Logical NOT (!)
    33. Logical OR (||)
    34. Logical OR assignment (||=)
    35. Logical nullish assignment (??=)
    36. Multiplication (*)
    37. Multiplication assignment (*=)
    38. Nullish coalescing operator (??)
    39. Object initializer
    40. 运算符优先级
    41. Optional chaining (?.)
    42. Pipeline operator (|>)
    43. 特性访问器
    44. Remainder (%)
    45. Remainder assignment (%=)
    46. Right shift (>>)
    47. Right shift assignment (>>=)
    48. Spread syntax (...)
    49. Strict equality (===)
    50. Strict inequality (!==)
    51. Subtraction (-)
    52. Subtraction assignment (-=)
    53. Unary negation (-)
    54. Unary plus (+)
    55. Unsigned right shift (>>>)
    56. Unsigned right shift assignment (>>>=)
    57. 异步函数表达式
    58. await
    59. class expression
    60. delete operator
    61. function* 表达式
    62. in operator
    63. instanceof
    64. new operator
    65. new.target
    66. super
    67. this
    68. typeof
    69. void 运算符
    70. yield
    71. yield*
  10. 语句 & 声明
    1. async function
    2. block
    3. break
    4. class
    5. const
    6. continue
    7. debugger
    8. do...while
    9. empty
    10. export
    11. for
    12. for await...of
    13. for...in
    14. for...of
    15. 函数声明
    16. function*
    17. if...else
    18. import
    19. import.meta
    20. label
    21. let
    22. return
    23. switch
    24. throw
    25. try...catch
    26. var
    27. while
    28. with
  11. 函数
    1. 箭头函数表达式
    2. 默认参数
    3. 方法定义
    4. 其余参数
    5. 自变量对象
    6. getter
    7. setter
    1. Private class fields
    2. Public class fields
    3. 构造函数
    4. extends
    5. static
  12. 错误
    1. Error: Permission denied to access property "x"
    2. InternalError: too much recursion
    3. RangeError: argument is not a valid code point
    4. RangeError: invalid array length
    5. RangeError: invalid date
    6. RangeError: precision is out of range
    7. RangeError: radix must be an integer
    8. RangeError: repeat count must be less than infinity
    9. RangeError: repeat count must be non-negative
    10. ReferenceError: "x" is not defined
    11. ReferenceError: assignment to undeclared variable "x"
    12. ReferenceError: can't access lexical declaration`X' before initialization
    13. ReferenceError: deprecated caller or arguments usage
    14. ReferenceError: invalid assignment left-hand side
    15. ReferenceError: reference to undefined property "x"
    16. SyntaxError: "0"-prefixed octal literals and octal escape seq. are deprecated
    17. SyntaxError: "use strict" not allowed in function with non-simple parameters
    18. SyntaxError: "x" is a reserved identifier
    19. SyntaxError: JSON.parse: bad parsing
    20. SyntaxError: Malformed formal parameter
    21. SyntaxError: Unexpected token
    22. SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
    23. SyntaxError: a declaration in the head of a for-of loop can't have an initializer
    24. SyntaxError: applying the 'delete' operator to an unqualified name is deprecated
    25. SyntaxError: for-in loop head declarations may not have initializers
    26. SyntaxError: function statement requires a name
    27. SyntaxError: identifier starts immediately after numeric literal
    28. SyntaxError: illegal character
    29. SyntaxError: invalid regular expression flag "x"
    30. SyntaxError: missing ) after argument list
    31. SyntaxError: missing ) after condition
    32. SyntaxError: missing : after property id
    33. SyntaxError: missing ; before statement
    34. SyntaxError: missing = in const declaration
    35. SyntaxError: missing ] after element list
    36. SyntaxError: missing formal parameter
    37. SyntaxError: missing name after . operator
    38. SyntaxError: missing variable name
    39. SyntaxError: missing } after function body
    40. SyntaxError: missing } after property list
    41. SyntaxError: redeclaration of formal parameter "x"
    42. SyntaxError: return not in function
    43. SyntaxError: test for equality (==) mistyped as assignment (=)?
    44. SyntaxError: unterminated string literal
    45. TypeError: "x" has no properties
    46. TypeError: "x" is (not) "y"
    47. TypeError: "x" is not a constructor
    48. TypeError: "x" is not a function
    49. TypeError: "x" is not a non-null object
    50. TypeError: "x" is read-only
    51. TypeError: 'x' is not iterable
    52. TypeError: More arguments needed
    53. TypeError: Reduce of empty array with no initial value
    54. TypeError: X.prototype.y called on incompatible type
    55. TypeError: can't access dead object
    56. TypeError: can't access property "x" of "y"
    57. TypeError: can't assign to property "x" on "y": not an object
    58. TypeError: can't define property "x": "obj" is not extensible
    59. TypeError: can't delete non-configurable array element
    60. TypeError: can't redefine non-configurable property "x"
    61. TypeError: cannot use 'in' operator to search for 'x' in 'y'
    62. TypeError: cyclic object value
    63. TypeError: invalid 'instanceof' operand 'x'
    64. TypeError: invalid Array.prototype.sort argument
    65. TypeError: invalid arguments
    66. TypeError: invalid assignment to const "x"
    67. TypeError: property "x" is non-configurable and can't be deleted
    68. TypeError: setting getter-only property "x"
    69. TypeError: variable "x" redeclares argument
    70. URIError: malformed URI sequence
    71. Warning: -file- is being assigned a //# sourceMappingURL, but already has one
    72. Warning: 08/09 is not a legal ECMA-262 octal constant
    73. Warning: Date.prototype.toLocaleFormat is deprecated
    74. Warning: JavaScript 1.6's for-each-in loops are deprecated
    75. Warning: String.x is deprecated; use String.prototype.x instead
    76. Warning: expression closures are deprecated
    77. Warning: unreachable code after return statement
  13. 杂项
    1. JavaScript technologies overview
    2. 词汇语法
    3. JavaScript 数据结构
    4. Enumerability and ownership of properties
    5. Iteration protocols
    6. 严格模式
    7. Transitioning to strict mode
    8. Template literals
    9. 弃用特征