選單
×
我的 W3Schools 獲取證書 Spaces 教師 Spaces 教師 Plus 獲取證書 Spaces 教師 Plus
   ❮     
HTML CSS JAVASCRIPT SQL PYTHON JAVA PHP HOW TO W3.CSS C C++ C# BOOTSTRAP REACT MYSQL JQUERY EXCEL XML DJANGO NUMPY PANDAS NODEJS R TYPESCRIPT ANGULAR GIT POSTGRESQL MONGODB ASP AI GO KOTLIN SASS VUE DSA GEN AI SCIPY AWS CYBERSECURITY DATA SCIENCE
     ❯   

JS 參考手冊

按類別劃分的 JS 按字母劃分的 JS

JavaScript

JS 陣列
Array[ ] 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() reverse() shift() slice() some() sort() splice() toReversed() toSorted() toSpliced() toString() unshift() values() valueOf() with()
JS 布林值
constructor prototype toString() valueOf()
JS 類
constructor() extends static super
JS 日期
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 錯誤
name message
JS 全域性
decodeURI() decodeURIComponent() encodeURI() encodeURIComponent() escape() eval() Infinity isFinite() isNaN() NaN Number() parseFloat() parseInt() String() undefined unescape()
JS JSON
parse() stringify()
JS Map
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() 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 數字
constructor EPSILON isFinite() isInteger() isNaN() isSafeInteger() MAX_SAFE_INTEGER MIN_SAFE_INTEGER MAX_VALUE MIN_VALUE NaN NEGATIVE_INFINITY POSITIVE_INFINITY parseFloat() parseInt() prototype toExponential() toFixed() toLocaleString() toPrecision() toString() valueOf()
JS 物件
assign() constructor create() defineProperties() defineProperty() entries() freeze() fromEntries() getOwnPropertyDescriptor() getOwnPropertyDescriptors() getOwnPropertyNames() groupBy() isExtensible() isFrozen() isSealed() keys() preventExtensions() prototype seal() toString() valueOf() values()
JS 運算子 JS 優先順序 JS Promise
all() allSettled() any() catch() finally() race() reject() resolve() then()
JS 正則表示式
修飾符: g i d m 組: [abc] [^abc] [0-9] [^0-9] (x|y) 元字元: . \w \W \d \D \s \S \b \B \0 \n \f \r \t \v \xxx \xdd \uxxxx 量詞: + * ? {X} {X,Y} {X,} $ ^ ?= ?! 屬性: constructor global ignoreCase lastIndex multiline source 方法: compile() exec() test() toString()
JS Set
new Set add() clear() delete() entries() forEach() has() keys() size values()
JS 語句
break class const continue debugger do...while for for...in for...of function if...else let return switch throw try...catch var while
JS 字串
at() charAt() charCodeAt() codePointAt() concat() constructor endsWith() fromCharCode() includes() indexOf() lastIndexOf() length localeCompare() match() padEnd() padStart() prototype repeat() replace() replaceAll() search() slice() split() startsWith() substr() substring() toLocaleLowerCase() toLocaleUpperCase() toLowerCase() toString() toUpperCase() trim() trimEnd() trimStart() valueOf()
JS TypedArray

Window

Window 物件
addeventlistener() alert() atob() blur() btoa() clearInterval() clearTimeout() close() closed confirm() console defaultStatus document focus() frameElement frames history getComputedStyle() innerHeight innerWidth length localStorage location matchMedia() moveBy() moveTo() name navigator open() opener outerHeight outerWidth pageXOffset pageYOffset parent print() prompt() removeEventlistener() resizeBy() resizeTo() screen screenLeft screenTop screenX screenY scrollBy() scrollTo() scrollX scrollY sessionStorage self setInterval() setTimeout() status stop() top
Window Console
assert() clear() count() error() group() groupCollapsed() groupEnd() info() log() table() time() timeEnd() trace() warn()
Window History
back() forward() go() length
Window Location
assign() hash host hostname href origin pathname port protocol reload() replace() search
Window Navigator
appCodeName appName appVersion cookieEnabled geolocation javaEnabled() language onLine platform product taintEnabled() userAgent
Window Screen
availHeight availWidth colorDepth height pixelDepth width

HTML DOM

HTML 文件
activeElement addEventListener() adoptNode() anchors applets baseURI body charset characterSet close() cookie createAttribute() createComment() createDocumentFragment() createElement() createEvent() createTextNode() defaultView designMode doctype documentElement documentMode documentURI domain domConfig embeds execCommand() forms getElementById() getElementsByClassName() getElementsByName() getElementsByTagName() hasFocus() head images implementation importNode() inputEncoding lastModified links normalize() normalizeDocument() open() querySelector() querySelectorAll() readyState referrer removeEventListener() renameNode() scripts strictErrorChecking title URL write() writeln()
HTML 元素
accessKey addEventListener() appendChild() attributes blur() childElementCount childNodes children classList className click() clientHeight clientLeft clientTop clientWidth cloneNode() closest() compareDocumentPosition() contains() contentEditable dir firstChild firstElementChild focus() getAttribute() getAttributeNode() getBoundingClientRect() getElementsByClassName() getElementsByTagName() hasAttribute() hasAttributes() hasChildNodes() id innerHTML innerText insertAdjacentElement() insertAdjacentHTML() insertAdjacentText() insertBefore() isContentEditable isDefaultNamespace() isEqualNode() isSameNode() isSupported() lang lastChild lastElementChild matches() namespaceURI nextSibling nextElementSibling nodeName nodeType nodeValue normalize() offsetHeight offsetWidth offsetLeft offsetParent offsetTop outerHTML outerText ownerDocument parentNode parentElement previousSibling previousElementSibling querySelector() querySelectorAll() remove() removeAttribute() removeAttributeNode() removeChild() removeEventListener() replaceChild() scrollHeight scrollIntoView() scrollLeft scrollTop scrollWidth setAttribute() setAttributeNode() style tabIndex tagName textContent title
HTML 屬性
getNamedItem() isId item() length name removeNamedItem() setNamedItem() specified value
HTML 集合
item() length namedItem()
HTML NodeList
entries() forEach() item() keys() length values()
HTML DOMTokenList
add() contains() entries() forEach() item() keys() length remove() replace() supports() toggle() value values()
HTML 樣式
alignContent alignItems alignSelf animation animationDelay animationDirection animationDuration animationFillMode animationIterationCount animationName animationTimingFunction animationPlayState background backgroundAttachment backgroundClip backgroundColor backgroundImage backgroundOrigin backgroundPosition backgroundRepeat backgroundSize backfaceVisibility border borderBottom borderBottomColor borderBottomLeftRadius borderBottomRightRadius borderBottomStyle borderBottomWidth borderCollapse borderColor borderImage borderImageOutset borderImageRepeat borderImageSlice borderImageSource borderImageWidth borderLeft borderLeftColor borderLeftStyle borderLeftWidth borderRadius borderRight borderRightColor borderRightStyle borderRightWidth borderSpacing borderStyle borderTop borderTopColor borderTopLeftRadius borderTopRightRadius borderTopStyle borderTopWidth borderWidth bottom boxShadow boxSizing captionSide caretColor clear clip color columnCount columnFill columnGap columnRule columnRuleColor columnRuleStyle columnRuleWidth columns columnSpan columnWidth counterIncrement counterReset cssFloat cursor direction display emptyCells filter flex flexBasis flexDirection flexFlow flexGrow flexShrink flexWrap font fontFamily fontSize fontStyle fontVariant fontWeight fontSizeAdjust height isolation justifyContent left letterSpacing lineHeight listStyle listStyleImage listStylePosition listStyleType margin marginBottom marginLeft marginRight marginTop maxHeight maxWidth minHeight minWidth objectFit objectPosition opacity order orphans outline outlineColor outlineOffset outlineStyle outlineWidth overflow overflowX overflowY padding paddingBottom paddingLeft paddingRight paddingTop pageBreakAfter pageBreakBefore pageBreakInside perspective perspectiveOrigin position quotes resize right scrollBehavior tableLayout tabSize textAlign textAlignLast textDecoration textDecorationColor textDecorationLine textDecorationStyle textIndent textOverflow textShadow textTransform top transform transformOrigin transformStyle transition transitionProperty transitionDuration transitionTimingFunction transitionDelay unicodeBidi userSelect verticalAlign visibility width wordBreak wordSpacing wordWrap widows zIndex

HTML 事件

HTML 事件
abort afterprint animationend animationiteration animationstart beforeprint beforeunload blur canplay canplaythrough change click contextmenu copy cut dblclick drag dragend dragenter dragleave dragover dragstart drop durationchange ended error focus focusin focusout fullscreenchange fullscreenerror hashchange input invalid keydown keypress keyup load loadeddata loadedmetadata loadstart message mousedown mouseenter mouseleave mousemove mouseover mouseout mouseup offline online open pagehide pageshow paste pause play playing progress ratechange resize reset scroll search seeked seeking select show stalled submit suspend timeupdate toggle touchcancel touchend touchmove touchstart transitionend unload volumechange waiting wheel
HTML 事件物件
動畫事件 剪貼簿事件 拖放事件 事件 焦點事件 雜湊變化事件 輸入事件 鍵盤事件 滑鼠事件 頁面過渡事件 PopState 事件 進度事件 儲存事件 觸控事件 過渡事件 UI 事件 滾輪事件
HTML 事件屬性
altKey (滑鼠) altKey (鍵盤) animationName bubbles button buttons cancelable charCode clientX clientY code ctrlKey (滑鼠) ctrlKey (鍵盤) currentTarget data defaultPrevented deltaX deltaY deltaZ deltaMode detail elapsedTime elapsedTime eventPhase inputType isTrusted key keyCode location metaKey (滑鼠) metaKey (鍵盤) newURL oldURL offsetX offsetY pageX pageY persisted propertyName relatedTarget relatedTarget screenX screenY shiftKey (滑鼠) shiftKey (鍵盤) target targetTouches timeStamp touches type which (滑鼠) which (鍵盤) view
HTML 事件方法
getModifierState() preventDefault() stopImmidiatePropagation() stopPropagation()

Web API

API Canvas API Console API Fetch API Fullscreen
exitFullscreen() fullscreenElement fullscreenEnabled() requestFullscreen()
API 地理位置
coordinates getCurrentPosition() position
API History API MediaQueryList API Storage
clear() getItem() key() length removeItem() setItem()
API 驗證 API Web
crypto.getRandomNumber()

HTML 物件

<a> <abbr> <address> <area> <article> <aside> <audio> <b> <base> <bdo> <blockquote> <body> <br> <button> <canvas> <caption> <cite> <code> <col> <colgroup> <datalist> <dd> <del> <details> <dfn> <dialog> <div> <dl> <dt> <em> <embed> <fieldset> <figcaption> <figure> <footer> <form> <head> <header> <h1> - <h6> <hr> <html> <i> <iframe> <img> <ins> <input> 按鈕 <input> 複選框 <input> 顏色 <input> 日期 <input> 日期和時間 <input> 本地日期和時間 <input> 電子郵件 <input> 檔案 <input> 隱藏 <input> 影像 <input> 月份 <input> 數字 <input> 密碼 <input> 單選按鈕 <input> 滑塊 <input> 重置 <input> 搜尋 <input> 提交 <input> 文字 <input> 時間 <input> URL <input> 周 <kbd> <label> <legend> <li> <link> <map> <mark> <menu> <menuitem> <meta> <meter> <nav> <object> <ol> <optgroup> <option> <output> <p> <param> <pre> <progress> <q> <s> <samp> <script> <section> <select> <small> <source> <span> <strong> <style> <sub> <summary> <sup> <table> <tbody> <td> <tfoot> <th> <thead> <tr> <textarea> <time> <title> <track> <u> <ul> <var> <video>

其他參考

CSSStyleDeclaration
cssText getPropertyPriority() getPropertyValue() item() length parentRule removeProperty() setProperty()
JS 轉換


JavaScript Math.SQRT1_2

❮ 上一個 JavaScript Math 物件 下一個 ❯

示例

let x = Math.SQRT1_2;
自己動手試一試 »

描述

Math.SQRT1_2 屬性返回 1/2 的平方根。

Math.SQRT1_2 屬性返回大約 0.707。

另請參閱

Math.sqrt() 方法
Math.cbrt() 方法
Math.SQRT2 屬性

語法

Math.SQRT1_2

返回值

型別 描述
Number1/2 的平方根。

相關頁面

JavaScript Math

JavaScript 數字

JavaScript Number 參考

瀏覽器支援

Math.SQRT1_2 是 ECMAScript1 (ES1) 功能。

ES1 (JavaScript 1997) 在所有瀏覽器中都得到完全支援

Chrome Edge Firefox Safari Opera IE
是 是 是 是 是 是

❮ 上一個 JavaScript Math 物件 下一個 ❯
PLUS
空格
獲取證書
面向教師
面向企業
聯絡我們
×

聯絡銷售

如果您想將 W3Schools 服務用於教育機構、團隊或企業，請傳送電子郵件給我們
sales@w3schools.com

報告錯誤

如果您想報告錯誤，或想提出建議，請傳送電子郵件給我們
help@w3schools.com

熱門教程
HTML 教程
CSS 教程
JavaScript 教程
操作方法教程
SQL 教程
Python 教程
W3.CSS 教程
Bootstrap 教程
PHP 教程
Java 教程
C++ 教程
jQuery 教程
熱門參考
HTML 參考
CSS 參考
JavaScript 參考
SQL 參考
Python 參考
W3.CSS 參考
Bootstrap 參考
PHP 參考
HTML 顏色
Java 參考
Angular 參考
jQuery 參考
熱門示例
HTML 示例
CSS 示例
JavaScript 示例
操作方法示例
SQL 示例
Python 示例
W3.CSS 示例
Bootstrap 示例
PHP 示例
Java 示例
XML 示例
jQuery 示例
獲取證書
 HTML 證書
CSS 證書
JavaScript 證書
前端證書
SQL 證書
Python 證書
PHP 證書
jQuery 證書
Java 證書
C++ 證書
C# 證書
XML 證書
論壇 關於 學院
W3Schools 經過最佳化，旨在方便學習和培訓。示例可能經過簡化，以提高閱讀和學習體驗。
教程、參考資料和示例會不斷審查，以避免錯誤，但我們無法保證所有內容的完全正確性。
使用 W3Schools 即表示您已閱讀並接受我們的使用條款、Cookie 和隱私政策。

版權所有 1999-2024 Refsnes Data。保留所有權利。W3Schools 由 W3.CSS 提供支援。