请参阅MDN上有关expressions and operators和statements的文档。

基本关键字和通用表达式

this关键字：

• How does the "this" keyword work, and when should it be used?

var x = function()对比function x() - 函数声明语法

• var functionName = function() {} vs function functionName() {}

(function(){ ... })() - IIFE（立即调用的函数表达式）

• What is the purpose?、How is it called?
• Why does (function(){…})(); work but function(){…}(); doesn't?
• (function(){…})(); vs (function(){…}());
• shorter alternatives：
• !function(){…}(); - What does the exclamation mark do before the function?
• +function(){…}(); - JavaScript plus sign in front of function expression
• !function(){ }() vs (function(){ })()、! vs leading semicolon
• (function(window, undefined){…}(window));

someFunction()() - 返回其他函数的函数

• Two sets of parentheses after function call

=> - 等号，大于：箭头函数表达式语法

• What's the meaning of "=>" (an arrow formed from equals & greater than) in JavaScript?

|> - 管道，大于：管道操作员

• What does the "|>" operator do in JavaScript?

function*，yield，yield* - 在function或yield后加星号：生成函数

• What is "function*" in JavaScript?
• What's the yield keyword in JavaScript?
• Delegated yield (yield star, yield *) in generator functions

[ ... ]、[ value ]、Array() - 方括号：数组记法

• What’s the difference between "Array()" and "[]" while declaring a JavaScript array?
• What is array literal notation in javascript and when should you use it?

如果方括号出现在赋值语句（[a] = ...）的左侧，或者出现在函数的参数中，则它是一个destructuring assignment。

• Where can I get info on the object parameter syntax for JavaScript functions?

{ ... }、{ key: value }、{ [key]: value } -  curl 支架：对象文字语法（不要与块混淆）

• What do curly braces in JavaScript mean?
• Javascript object literal: what exactly is {a, b, c}?
• What do square brackets around a property name in an object literal mean?
• How does this object method definition work without the "function" keyword?（ES 2015方法定义）

如果花括号出现在赋值语句的左侧（{ a } = ...）或函数的参数中，则它是一个destructuring assignment。

... `${` ... `}` ... - 反引号，带花括号的美元符号：模板文字

• What does this …${…}… code from the node docs mean?
• Usage of the backtick character (`) in JavaScript?
• What is the purpose of template literals (backticks) following a function in ES6?

/ ... / - 斜线：正则表达式文字

• Meaning of javascript text between two slashes

$ - 正则表达式中的美元符号替换模式：$$、$&、$``、$'、$ `n``

• JavaScript replace() method dollar signs

() - 括号：分组算子

• MDN: Grouping operator

属性相关表达式

obj.prop，obj[prop]，obj["prop"] - 方括号或圆点：属性访问器

• JavaScript property access: dot notation vs. brackets?

?.，?.[]，?.() - 问号，点：任选链接算子

• Question mark after parameter
• Null-safe property access (and conditional assignment) in ES6/2015
• Optional Chaining in JavaScript
• Is there a null-coalescing (Elvis) operator or safe navigation operator in javascript?
• Is there a "null coalescing" operator in JavaScript?

:: - 双冒号：结合运算子

• JavaScript double colon (bind operator)

new运算符

• What is the 'new' keyword in JavaScript?
• What is "new.target"?

...iter - 三点：spread语法;静止参数

• (...rest) => {} - What is the meaning of “…args” (three dots) in a function definition?
• fn(...args) - What is the meaning of “foo(…arg)” (three dots in a function call)?
• [...iter] - javascript es6 array feature […data, 0] “spread operator”
• {...props} - Javascript Property with three dots (…)，What does the '…rest' stand for in this object destructuring?

增量和减量

++，-- - 双正负：前/后递增/递减运算符

• ++someVariable vs someVariable++ in Javascript

一元和二元（算术、逻辑、位）运算符

delete运算符

• What is the purpose of the delete operator in Javascript?

void运算符

• What does void 0 mean?

+，- - 加减：加法或串联，以及减法运算符;一元符号算子

• What does = +_ mean in JavaScript、Single plus operator in javascript
• What's the significant use of unary plus and minus operators?
• Why is [1,2] + [3,4] = "1,23,4" in JavaScript?
• Why does JavaScript handle the plus and minus operators between strings and numbers differently?

|、&、^、~ - 单管道、与号、扬抑符、波浪号：按位OR、AND、XOR和NOT运算符

• What do these JavaScript bitwise operators do?
• How to: The ~ operator?
• Is there a & logical operator in Javascript
• What does the "|" (single pipe) do in JavaScript?
• What does the operator |= do in JavaScript?
• What does the ^ (caret) symbol do in JavaScript?
• Using bitwise OR 0 to floor a number、How does x|0 floor the number in JavaScript?
• Why does ~1 equal -2 ?
• What does ~~ ("double tilde") do in Javascript?
• How does !!~ (not not tilde/bang bang tilde) alter the result of a 'contains/included' Array method call?（也称为here和here）

% - 百分号：余运算符

• What does % do in JavaScript?

&&，||，! - 双“和”号、双竖线、感叹号：逻辑运算符

• Logical operators in JavaScript — how do you use them?
• Logical operator || in javascript, 0 stands for Boolean false?
• What does "var FOO = FOO || {}" (assign a variable or an empty object to that variable) mean in Javascript?、JavaScript OR (||) variable assignment explanation、What does the construct x = x || y mean?
• Javascript AND operator within assignment
• What is "x && foo()"?（也称为here和here）
• What is the !! (not not) operator in JavaScript?
• What is an exclamation point in JavaScript?

?? - 双问号：零合并算子

• How is the nullish coalescing operator (??) different from the logical OR operator (||) in ECMAScript?
• Is there a null-coalescing (Elvis) operator or safe navigation operator in javascript?
• Is there a "null coalescing" operator in JavaScript?

** - 星星：幂运算符（取幂）

• x ** 2等同于Math.pow(x, 2)
• Is the double asterisk ** a valid JavaScript operator?
• MDN documentation

等号运算符

==，=== - 等号：等式运算符

• Which equals operator (== vs ===) should be used in JavaScript comparisons?
• How does JS type coercion work?
• In Javascript, == "" evaluates to true. Why is it so?
• [] == ![] evaluates to true
• Why does "undefined equals false" return false?
• Why does !new Boolean(false) equals false in JavaScript?
• Javascript 0 == '0'. Explain this example
• Why false == "false" is false?

!=，!== - 感叹号和等号：不等式算子

• != vs. !==
• What is the difference between != and !== operators in JavaScript?

移位运算符

<<，>>，>>> - 两个或三个尖括号：位元移位运算子

• What do these JavaScript bitwise operators do?
• Double more-than symbol in JavaScript
• What is the JavaScript >>> operator and how do you use it?

条件运算符

... ? ... : ... - 问号和冒号：条件（三元）运算符

• Question mark and colon in JavaScript
• Operator precedence with JavaScript's ternary operator
• How do you use the ? : (conditional) operator in JavaScript?

赋值运算符

= - 等号：赋值运算符

• What is the difference between the = and == operators and what is ===? (Single, double, and triple equals)

此符号也用于destructuring assignment中的 default parameters 或 default values：

• What does (state = {}) => state mean?
• What does ({"key": "value"} = {}) syntax mean inside a JavaScript function

%= - 百分比等于：余数赋值

• Having Confusion with Modulo operator

+= - 加等于：加法赋值运算符

• How does += (plus equal) work?

&&=，||=，??= - 双“与”、竖线或问号，后跟等号：逻辑赋值

• What purpose do &&=, ||= and ??= serve?
• Replace a value if null or undefined in JavaScript
• Set a variable if undefined
• Ruby’s ||= (or equals) in JavaScript?
• Original proposal
• 产品规格

<<=，>>=，>>>=，&=，^=，|=-双小于、双大于、三大于、和号、插入符号或后接等号的竖线：按位赋值

• What do these JavaScript bitwise operators do?

销毁

• 函数参数：Where can I get info on the object parameter syntax for JavaScript functions?
• 数组：Multiple assignment in JavaScript? What does [ a, b, c ] = [ 1, 2, 3 ] mean?
• 对象/进口：Javascript object bracket notation ({ Navigation } =) on left side of assign

逗号运算符

, - 逗号运算符（不要与变量声明中使用的逗号混淆）

• What does the comma operator do in JavaScript?
• Comma operator returns first value instead of second in argument list?
• When is the comma operator useful?

控制流程

{ ... } - curl 括号：块（不要与对象文字语法混淆）

• JavaScript curly braces with no function or json

声明

var，let，const - 声明变量

• What is the difference between "let" and "var"?
• Are there constants in JavaScript?
• What is the temporal dead zone?
• var a, b; - 变量声明中使用的逗号（不要与逗号运算符混淆）：JavaScript variable definition: Commas vs. Semicolons

标签

label: - 冒号：标签

• What does the JavaScript syntax foo: mean?
• What does ':' (colon) do in JavaScript?

其他

整数后的123n - n：BigInt

• What does character 'n' after numeric literal mean in JavaScript?

# - Hash（数字符号）：私有方法或私有字段

• What does the # symbol do in JavaScript?

_ - Underscore：数字文本中的分隔符

• Javascript numeric separators?
• Is there a Javascript equivalent to the Ruby syntax using underscores (e.g. 10_000 = 10000) to make larger integers human readable?