导航
×
CSS 教程 JAVASCRIPT 教程 PHP 教程 HTML 教程 测验
   ❮   
HTML CSS JavaScript PHP Go Sass W3C Colors ECMS

JS 参考手册

JS 参考手册（字母排序）

JavaScript

JS Arrays
Array( ) at() concat() constructor copyWithin() entries() every() fill() filter() find() findIndex() findLast() findLastIndex() flat() flatMap() forEach() from() includes() indexOf() isArray() join() keys() lastIndexOf() length map() of() pop() prototype push() reduce() reduceRight() rest (...) reverse() shift() slice() some() sort() splice() spread (...) toReversed() toSorted() toSpliced() toString() unshift() values() valueOf() with()
JS Boolean
Boolean() new Boolean() constructor prototype toString() valueOf()
JS Classes
constructor() extends static super
JS Dates
new Date() constructor getDate() getDay() getFullYear() getHours() getMilliseconds() getMinutes() getMonth() getSeconds() getTime() getTimezoneOffset() getUTCDate() getUTCDay() getUTCFullYear() getUTCHours() getUTCMilliseconds() getUTCMinutes() getUTCMonth() getUTCSeconds() now() parse() prototype setDate() setFullYear() setHours() setMilliseconds() setMinutes() setMonth() setSeconds() setTime() setUTCDate() setUTCFullYear() setUTCHours() setUTCMilliseconds() setUTCMinutes() setUTCMonth() setUTCSeconds() toDateString() toISOString() toJSON() toLocaleDateString() toLocaleTimeString() toLocaleString() toString() toTimeString() toUTCString() UTC() valueOf()
JS Error
isError() name message
JS Global
decodeURI() decodeURIComponent() encodeURI() encodeURIComponent() escape() eval() Infinity isFinite() isNaN() NaN Number() parseFloat() parseInt() String() undefined unescape()
JS Iterators
drop() every() filter() find() flatMap() forEach() map() reduce() some() take()
JS JSON
parse() stringify()
JS Maps
new Map clear() delete() entries() forEach() get() groupBy() has() keys() set() size values()
JS Math
abs() acos() acosh() asin() asinh() atan() atan2() atanh() cbrt() ceil() clz32() cos() cosh() E exp() expm1() f16round() floor() fround() LN2 LN10 log() log10() log1p() log2() LOG2E LOG10E max() min() PI pow() random() round() sign() sin() sinh() sqrt() SQRT1_2 SQRT2 tan() tanh() trunc()
JS Numbers
constructor EPSILON isFinite() isInteger() isNaN() isSafeInteger() MAX_SAFE_INTEGER MIN_SAFE_INTEGER MAX_VALUE MIN_VALUE NEGATIVE_INFINITY POSITIVE_INFINITY parseFloat() parseInt() prototype toExponential() toFixed() toLocaleString() toPrecision() toString() valueOf() NaN
JS Objects
assign() constructor create() defineProperties() defineProperty() delete entries() freeze() fromEntries() getOwnPropertyDescriptor() getOwnPropertyDescriptors() getOwnPropertyNames() groupBy() isExtensible() isFrozen() isSealed() keys() preventExtensions() prototype seal() toString() valueOf() values()
JS Operators JS Assignment
Assign Simple Assign Add Assign Subtract Assign Multiply Assign Divide Assign Remainder Assign Colon Assign AND Assign OR Assign Nullish
JS Arithmetic
Addition Subtraction Multiplication Division Exponentiation Remainder Increment Decrement Concatenation Unary Plus Unary Negation
JS Comparison
Equal Strict Equal Not Equal Strict Not Equal Greater Than Less Than Greater Equal Less Equal
JS Logical Operators
Logical AND Logical OR Logical NOT Logical Nullish
JS Bitwise Operators
Bitwise AND Bitwise OR Bitwise NOT Bitwise XOR Bitwise Left Bitwise Right Bitwise Signed
JS Misc Operators
: ?. ... () ? x : y => delete in instanceof typeof void
JS Precedence JS Promises
all() allSettled() any() catch() finally() race() reject() resolve() then()
JS RegExp Patterns
/d /g /i /m /s /u /v /y [a] [^a] [abc] [^abc] [A-Z] [^A-Z] [0-9] [^0-9] a|b . \w \W \d \D \s \S [\b] \0 \n \f \r \t \v \p \P \ddd \xdd \udddd ^ $ \b \B x(?=y) x(?!y) (?<=y)x (?<!y)x (x) (?<name>x) (?flags:x) + * ? {n} {n,m} {n,}
JS RegExp Reference
compile() constructor dotAll escape() exec() flags global hasIndices ignoreCase lastIndex multiline source sticky test() toString() unicode unicodeSets
JS Sets
new Set add() clear() delete() difference() entries() forEach() has() intersection() isDisjointFrom() isSubsetOf() isSupersetOf() keys() size symmetricDifference() union() values()
JS Statements
break class const continue debugger do...while for for...in for...of function if...else let return switch throw try...catch var while
JS Strings
at() charAt() charCodeAt() codePointAt() concat() constructor endsWith() fromCharCode() includes() indexOf() isWellFormed() lastIndexOf() length localeCompare() match() matchAll() padEnd() padStart() prototype repeat() replace() replaceAll() search() slice() split() startsWith() substr() substring() toLocaleLowerCase() toLocaleUpperCase() toLowerCase() toString() toUpperCase() toWellFormed() trim() trimEnd() trimStart() valueOf()

JavaScript OR 逻辑或运算符

❮ 上一个 完整 JS 参考 下一个 ❯

示例

let voteable = (age< 18) ? "太年轻":"已成年";
亲自试一试 »

如果变量 age 的值小于 18，则变量 voteable 的值为"太年轻"，否则值为"足够大"。

描述

条件运算符是编写条件语句(if...else)的简写形式。

它被称为三元运算符，因为它接受三个操作数。

语法

(condition) ? value1:value2

了解更多:

JavaScript 运算符

赋值运算符

算术运算符

比较运算符

逻辑运算符

位运算符

其他运算符

浏览器支持

() ? x : y 是 ECMAScript 1(JavaScript 1997)的一项特性。

所有浏览器均支持此功能。

Chrome Edge Firefox Safari Opera
❮ 上一节 下一节 ❯
关于我们
免责声明
隐私条款
学习路线
关于我们
免责声明
Copyright ©2020-2026 freew3c.com All Rights Reserved 提供的内容仅用于学习和测试，不保证内容的正确性。