JS 参考手册

JS 参考手册(类别排序) JS 参考手册(字母排序)

JavaScript

JS Array JS Boolean JS Classes JS Date JS Error JS Global JS JSON JS Math JS Number JS 运算符 JS RegExp JS 语句 JS String

HTML DOM

DOM Attributes DOM Document DOM Element DOM Events DOM Event 对象 DOM HTMLCollection DOM Location DOM Navigator DOM Screen DOM Style
alignContent alignItems alignSelf animation animationDelay animationDirection animationDuration animationFillMode animationIterationCount animationName animationTimingFunction animationPlayState background backgroundAttachment backgroundColor backgroundImage backgroundPosition backgroundRepeat backgroundClip backgroundOrigin 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 cursor direction display emptyCells filter flex flexBasis flexDirection flexFlow flexGrow flexShrink flexWrap cssFloat 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
DOM Window

Web APIs

API Console API Geolocation API History API Storage

HTML 对象

<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> button <input> checkbox <input> color <input> date <input> datetime <input> datetime-local <input> email <input> file <input> hidden <input> image <input> month <input> number <input> password <input> radio <input> range <input> reset <input> search <input> submit <input> text <input> time <input> url <input> week <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>

其他参考手册

CSSStyleDeclaration JS 类型转换


Input Text defaultValue 属性

❮ Input Text 对象

实例

更改文本字段的默认值:

document.getElementById("myText").defaultValue = "Goofy";
亲自试一试 »

定义和用法

defaultValue 属性设置或返回文本字段的默认值。

注释:默认值是 HTML value 属性中指定的值。

defaultValue 和 value 属性的区别在于 defaultValue 包含默认值,而 value 包含经过一些更改后的当前值。 如果没有更改,则 defaultValue 和 value 相同(请参阅下面的"更多示例")。

当您想查明文本字段的内容是否已更改时,defaultValue 属性很有用。


浏览器支持

属性
defaultValue Yes Yes Yes Yes Yes

语法

返回 defaultValue 属性:

textObject.defaultValue

设置 defaultValue 属性:

textObject.defaultValue = value

属性值

描述
value 指定文本字段的默认值


技术细节

返回值: 字符串,代表文本字段的默认值

更多实例

实例

获取文本字段的默认值:

var x = document.getElementById("myText").defaultValue;
亲自试一试 »

实例

一个展示defaultValue和value属性区别的例子:

var x = document.getElementById("myText");
var defaultVal = x.defaultValue;
var currentVal = x.value;
亲自试一试 »

❮ Input Text 对象