JavaScript Cheat Sheet, Cheat Sheet of Javascript programming

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Beginner’s essential JavaScript Cheat Sheet The Language of the Web. ################# TABLE OF CONTENTS JavaScript Basics 3 Variables in JavaScript 3 The Next Level: Arrays 4 Operators 5 Functions 6 JavaScript Loop 7 If - Else Statements 8 Strings 8 Regular Expression Syntax 9 Numbers and Math 11 Dealing with Dates in JavaScript 13 DOM Mode 14 Working with the User Browser 17 JavaScript Events 19 of 2 24 sort() — Sorts elements alphabetically splice() — Adds elements in a specified way and position toString() — Converts elements to strings unshift() — Adds a new element to the beginning valueOf() — Returns the first position at which a given element appears in an array OPERATORS Basic Operators + — Addition - — Subtraction * — Multiplication / — Division (...) — Grouping operator, operations within brackets are executed earlier than those outside % — Modulus (remainder ) ++ — Increment numbers -- — Decrement numbers Comparison Operators == — Equal to === — Equal value and equal type != — Not equal !== — Not equal value or not equal type > — Greater than < — Less than >= — Greater than or equal to of 5 24 <= — Less than or equal to ? — Ternary operator Logical Operators && — Logical and || — Logical or ! — Logical not Bitwise Operators & — AND statement | — OR statement ~ — NOT ^ — XOR << — Left shift >> — Right shift >>> — Zero fill right shift FUNCTIONS function name(parameter1, parameter2, parameter3) { // what the function does } Outputting Data alert() — Output data in an alert box in the browser window confirm() — Opens up a yes/no dialog and returns true/false depending on user click console.log() — Writes information to the browser console, good for debugging purposes of 6 24 document.write() — Write directly to the HTML document prompt() — Creates an dialogue for user input Global Functions decodeURI() — Decodes a Uniform Resource Identifier (URI) created by encodeURI or similar decodeURIComponent() — Decodes a URI component encodeURI() — Encodes a URI into UTF-8 encodeURIComponent() — Same but for URI components eval() — Evaluates JavaScript code represented as a string isFinite() — Determines whether a passed value is a finite number isNaN() — Determines whether a value is NaN or not Number() — Returns a number converted from its argument parseFloat() — Parses an argument and returns a floating point number parseInt() — Parses its argument and returns an integer JAVASCRIPT LOOPS for (before loop; condition for loop; execute after loop) { // what to do during the loop } for — The most common way to create a loop in JavaScript while — Sets up conditions under which aloop executes do while — Similar to the while loop, however, it executes at least once and performs a check at the end to see if the condition is met to execute again break — Used to stop and exit the cycle at certain conditions continue — Skip parts of the cycle if certain conditions are met of 7 24 x — Allow comments and whitespace in pattern U — Ungreedy pattern Brackets [abc] — Find any of the characters between the brackets [^abc] — Find any character not in the brackets [0-9] — Used to find any digit from 0 to 9 [A-z] — Find any character from uppercase A to lowercase z (a|b|c) — Find any of the alternatives separated with | Metacharacters . — Find a single character, except newline or line terminator \w — Word character \W — Non-word character \d — A digit \D — A non-digit character \s — Whitespace character \S — Non-whitespace character \b — Find a match at the beginning/end of a word \B — A match not at the beginning/end of a word \0 — NUL character \n — A new line character \f — Form feed character \r — Carriage return character \t — Tab character \v — Vertical tab character \xxx — The character specified by an octal number xxx of 10 24 \xdd — Character specified by a hexadecimal number dd \uxxxx — The Unicode character specified by a hexadecimal number xxxx Quantifiers n+ — Matches any string that contains at least one n n* — Any string that contains zero or more occurrences of n n? — A string that contains zero or one occurrences of n n{X} — String that contains a sequence of X n’s n{X,Y} — Strings that contains a sequence of X to Y n’s n{X,} — Matches any string that contains a sequence of at least X n’s n$ — Any string with n at the end of it ^n — String with n at the beginning of it ?=n — Any string that is followed by a specific string n ?!n — String that is not followed by a specific string n NUMBERS AND MATH Number Properties MAX_VALUE — The maximum numeric value representable in JavaScript MIN_VALUE — Smallest positive numeric value representable in JavaScript NaN — The “Not-a-Number” value NEGATIVE_INFINITY — The negative Infinity value POSITIVE_INFINITY — Positive Infinity value Number Methods toExponential() — Returns a string with a rounded number written as exponential notation of 11 24 toFixed() — Returns the string of a number with a specified number of decimals toPrecision() — String of a number written with a specified length toString() — Returns a number as a string valueOf() — Returns a number as a number Math Properties E — Euler’s number LN2 — The natural logarithm of 2 LN10 — Natural logarithm of 10 LOG2E — Base 2 logarithm of E LOG10E — Base 10 logarithm of E PI — The number PI SQRT1_2 — Square root of 1/2 SQRT2 — The square root of 2 Math Methods abs(x) — Returns the absolute (positive) value of x acos(x) — The arccosine of x, in radians asin(x) — Arcsine of x, in radians atan(x) — The arctangent of x as a numeric value atan2(y,x) — Arctangent of the quotient of its arguments ceil(x) — Value of x rounded up to its nearest integer cos(x) — The cosine of x (x is in radians) exp(x) — Value of Ex floor(x) — The value of x rounded down to its nearest integer log(x) — The natural logarithm (base E) of x of 12 24 nodeType — Returns the type of a node nodeValue — Sets or returns the value of a node ownerDocument — The top-level document object for this node parentNode — Returns the parent node of an element previousSibling — Returns the node immediately preceding the current one textContent — Sets or returns the textual content of a node and its descendants Node Methods appendChild() — Adds a new child node to an element as the last child node cloneNode() — Clones an HTML element compareDocumentPosition() — Compares the document position of two elements getFeature() — Returns an object which implements the APIs of a specified feature hasAttributes() — Returns true if an element has any attributes, otherwise false hasChildNodes() — Returns true if an element has any child nodes, otherwise false insertBefore() — Inserts a new child node before a specified, existing child node isDefaultNamespace() — Returns true if a specified namespaceURI is the default, otherwise false isEqualNode() — Checks if two elements are equal isSameNode() — Checks if two elements are the same node isSupported() — Returns true if a specified feature is supported on the element lookupNamespaceURI() — Returns the namespaceURI associated with a given node of 15 24 lookupPrefix() — Returns a DOMString containing the prefix for a given namespaceURI, if present normalize() — Joins adjacent text nodes and removes empty text nodes in an element removeChild() — Removes a child node from an element replaceChild() — Replaces a child node in an element Element Methods getAttribute() — Returns the specified attribute value of an element node getAttributeNS() — Returns string value of the attribute with the specified namespace and name getAttributeNode() — Gets the specified attribute node getAttributeNodeNS() — Returns the attribute node for the attribute with the given namespace and name getElementsByTagName() — Provides a collection of all child elements with the specified tag name getElementsByTagNameNS() — Returns a live HTMLCollection of elements with a certain tag name belonging to the given namespace hasAttribute() — Returns true if an element has any attributes, otherwise false hasAttributeNS() — Provides a true/false value indicating whether the current element in a given namespace has the specified attribute removeAttribute() — Removes a specified attribute from an element removeAttributeNS() — Removes the specified attribute from an element within a certain namespace removeAttributeNode() — Takes away a specified attribute node and returns the removed node setAttribute() — Sets or changes the specified attribute to a specified value setAttributeNS() — Adds a new attribute or changes the value of an attribute with the given namespace and name setAttributeNode() — Sets or changes the specified attribute node of 16 24 setAttributeNodeNS() — Adds a new namespaced attribute node to an element WORKING WITH THE USER BROWSER Window Properties closed — Checks whether a window has been closed or not and returns true or false defaultStatus — Sets or returns the default text in the statusbar of a window document — Returns the document object for the window frames — Returns all <iframe> elements in the current window history — Provides the History object for the window innerHeight — The inner height of a window’s content area innerWidth — The inner width of the content area length — Find out the number of <iframe> elements in the window location — Returns the location object for the window name — Sets or returns the name of a window navigator — Returns the Navigator object for the window opener — Returns a reference to the window that created the window outerHeight — The outer height of a window, including toolbars/ scrollbars outerWidth — The outer width of a window, including toolbars/ scrollbars pageXOffset — Number of pixels the current document has been scrolled horizontally pageYOffset — Number of pixels the document has been scrolled vertically parent — The parent window of the current window screen — Returns the Screen object for the window of 17 24 onmouseout — User moves the mouse pointer out of an element or one of its children onmouseup — The user releases a mouse button while over an element Keyboard onkeydown — When the user is pressing a key down onkeypress — The moment the user starts pressing a key onkeyup — The user releases a key Frame onabort — The loading of a media is aborted onbeforeunload — Event occurs before the document is about to be unloaded onerror — An error occurs while loading an external file onhashchange — There have been changes to the anchor part of a URL onload — When an object has loaded onpagehide — The user navigates away from a webpage onpageshow — When the user navigates to a webpage onresize — The document view is resized onscroll — An element’s scrollbar is being scrolled onunload — Event occurs when a page has unloaded Form onblur — When an element loses focus onchange — The content of a form element changes (for <input>, <select>and <textarea>) onfocus — An element gets focus onfocusin — When an element is about to get focus onfocusout — The element is about to lose focus of 20 24 oninput — User input on an element oninvalid — An element is invalid onreset — A form is reset onsearch — The user writes something in a search field (for <input="search">) onselect — The user selects some text (for <input> and <textarea>) onsubmit — A form is submitted Drag ondrag — An element is dragged ondragend — The user has finished dragging the element ondragenter — The dragged element enters a drop target ondragleave — A dragged element leaves the drop target ondragover — The dragged element is on top of the drop target ondragstart — User starts to drag an element ondrop — Dragged element is dropped on the drop target Clipboard oncopy — User copies the content of an element oncut — The user cuts an element’s content onpaste — A user pastes content in an element Media onabort — Media loading is aborted oncanplay — The browser can start playing media (e.g. a file has buffered enough) oncanplaythrough — When browser can play through media without stopping ondurationchange — The duration of the media changes of 21 24 onended — The media has reach its end onerror — Happens when an error occurs while loading an external file onloadeddata — Media data is loaded onloadedmetadata — Meta data (like dimensions and duration) are loaded onloadstart — Browser starts looking for specified media onpause — Media is paused either by the user or automatically onplay — The media has been started or is no longer paused onplaying — Media is playing after having been paused or stopped for buffering onprogress — Browser is in the process of downloading the media onratechange — The playing speed of the media changes onseeked — User is finished moving/skipping to a new position in the media onseeking — The user starts moving/skipping onstalled — The browser is trying to load the media but it is not available onsuspend — Browser is intentionally not loading media ontimeupdate — The playing position has changed (e.g. because of fast forward) onvolumechange — Media volume has changed (including mute) onwaiting — Media paused but expected to resume (for example, buffering) Animation animationend — A CSS animation is complete animationiteration — CSS animation is repeated animationstart — CSS animation has started Other of 22 24