JS Reference

JS by Category JS by Alphabet

JavaScript

JS Array JS Boolean JS Classes JS Date JS Error JS Global JS JSON JS Math JS Number JS Operators JS RegExp JS Statements JS String

Window

Window Object Window Console Window History Window Location Window Navigator Window Screen

HTML DOM

DOM Document DOM Element DOM Attributes DOM Events DOM Event Objects DOM HTMLCollection 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

Web APIs

API Console API Fullscreen API Geolocation API History API MediaQueryList API Storage

HTML Objects

<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>

Other References

CSSStyleDeclaration JS Conversion


JavaScript-konst

Konstante Skikking:

// Create an array:
const cars = ["Saab", "Volvo", "BMW"];

// Change an element:
cars[0] = "Toyota";

// Add an element:
cars.push("Audi");

Konstante voorwerp:

// Create an object:
const car = {type:"Fiat", model:"500", color:"white"};

// Change a property:
car.color = "red";

// Add a property:
car.owner = "Johnson";

Definisie en gebruik

Die conststelling verklaar 'n veranderlike.

Veranderlikes is houers vir die stoor van inligting.

Om 'n veranderlike in JavaScript te skep, word 'n veranderlike "verklaar" genoem:

const name = "Volvo";

Let wel

'n Const veranderlike moet toegeken word wanneer dit verklaar word.

Sien ook:

JavaScript-verwysing: JavaScript var

JavaScript-verwysing: JavaScript laat

Tutoriale:

JavaScript-tutoriaal: JavaScript-veranderlikes

JavaScript-tutoriaal: JavaScript-konst

JavaScript-tutoriaal: JavaScript laat

JavaScript-tutoriaal: JavaScript-omvang


Sintaksis

const name = value;

Grense

Parameter Description
name Required.
The name of the variable.
Variable names must follow these rules:

Must begin with a letter, or $, or _
Names are case sensitive (y and Y are different)
Reserved JavaScript words cannot be used as names
value Required.
A value to be assigned to the variable.


Wanneer om JavaScript const te gebruik?

As 'n algemene reël, verklaar altyd 'n veranderlike met consttensy jy weet dat die waarde sal verander.

Gebruik constwanneer jy verklaar:

  • 'n Nuwe Array
  • 'n Nuwe Voorwerp
  • 'n Nuwe funksie
  • 'n Nuwe RegExp

Blaaierondersteuning

constword in alle moderne blaaiers ondersteun:

Chrome IE Edge Firefox Safari Opera
Yes 11 Yes Yes Yes Yes

constis 'n ECMAScript6 (ES6 - JavaScript 2015) kenmerk.