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


Window prompt() 方法

❮ Window 对象

实例

显示提示框,询问用户姓名,并输出问候消息:

var person = prompt("Please enter your name", "Harry Potter");

if (person != null) {
  document.getElementById("demo").innerHTML =
  "Hello " + person + "! How are you today?";
}
亲自试一试 »

页面下方有更多实例。


定义和用法

prompt() 方法显示一个对话框,提示访问者进行输入。

如果希望用户在进入页面之前输入值,通常会使用提示框。

注释: 当弹出提示框时,用户必须在输入值后单击"确定"或"取消"继续。不要过度使用此方法,因为它会阻止用户在关闭框之前访问页面的其他部分。

如果用户单击"确定", prompt() 方法将返回输入值。如果用户单击"取消",该方法将返回 null。


浏览器支持

方法
prompt() Yes Yes Yes Yes Yes

语法

prompt(text, defaultText)

参数值

参数 类型 描述
text String 必需。 要在对话框中显示的文本
defaultText String 可选。 默认输入文本


技术细节

返回值: 字符串。如果用户单击"确定",则返回输入值。如果用户单击"取消",则返回 null。如果用户单击"确定"而不输入任何文本,则返回空字符串。

更多实例

实例

使用 switch 语句和 prompt() 根据用户输入执行一段代码:

var text;
var favDrink = prompt("What's your favorite cocktail drink?");
switch(favDrink) {
  case "Martini":
    text = "Excellent choice! Martini is good for your soul.";
    break;
  case "Daiquiri":
    text = "Daiquiri is my favorite too!";
    break;
  case "Cosmopolitan":
    text = "Really? Are you sure the Cosmopolitan is your favorite?";
    break;
  default:
    text = "I have never heard of that one..";
    break;
}
亲自试一试 »

相关页面

Window 对象: alert() 方法

Window 对象: confirm() 方法


❮ Window 对象