Objects and methods are predefined functions that perform specific tasks in javascript. They make the codes reusable and shorthand. Lets have a look at few of the most used javascript objects and methods.
| Method | Usage |
|---|---|
| concat() | Combines two existing Array objects to one |
| join() | Returns a string with elements from an Array |
| pop() | Removes the last value from an Array |
| push() | Appends a value to the end of an Array |
| reverse() | Reverse the order of elements in an Array |
| shift() | Removes the first value from an Array |
| slice() | Returns a subset from an Array |
| sort() | Sorts an Array |
| splice() | Adds new elements to an Array while removing old elements. |
| toLocaleString() | Returns a String with current locale format and separators |
| toSource() | String representing the source code of the object |
| toString() | Returns Array elements as string type separated by commas |
| unshift() | Inserts a value at the beginning of an Array |
| valueOf() | Returns Array elements as string type separated by commas |
| constructor() | Reference to the function that created an object |
| index() | Zero-based index of the match for array created by a regular expression match |
| input() | Original string used to match for array created by a regular expression match |
| length() | Returns the length of an Array |
| prototype() | Creates a new method for Array objects |
var colors = new Array('red', 'green', 'blue');
colors.push('black');
document.write(colors);
| Method | Usage |
| toSource() | String representing the source code of the object |
| toString() | Returns boolean value as string type |
| valueOf() | Returns an objects value as a Boolean type |
| constructor() | Reference to the function that created an object |
| prototype() | Creates a new method for Boolean objects |
var x = 3; result = x.valueOf(); document.write(result);
| Method | Usage |
| getDate() | Date as an integer between 1 and 31 |
| getDay() | Day of week value: 0=Sunday, 1=Monday |
| getYear() | Year value of a Date object |
| getFullYear() | 4 digit year of a Date object |
| getHours() | Hours value of a Date object (0-23) |
| getMilliseconds() | Milliseconds value of a Date object (0-999) |
| getMinutes() | Minutes value of a Date object (0-59) |
| getMonth() | Month value of a Date object (0=Jan, 11=Dec) |
| getSeconds() | Seconds value of a Date object (0-59) |
| getTime() | Milliseconds since 1970-1-1 of a Date object |
| getTimezoneOffset() | Minutes between local and UTC (GMT) time |
| getUTCDate() | Date value using UTC (GMT) time |
| getUTCDay() | Day of week using UTC (GMT) time (0=Sunday) |
| getUTCFullYear() | 4 digit year using UTC (GMT) time |
| getUTCHours() | Hours using UTC (GMT) time. (0-23) |
| getUTCMilliseconds() | Milliseconds using UTC (GMT) time (0-999) |
| getUTCMinutes() | Minutes using UTC (GMT) time (0-59) |
| getUTCMonth() | Month using UTC (GMT) time (0-11) |
| getUTCSeconds() | Seconds using UTC (GMT) time (0-59) |
| parse() | Milliseconds between parsed string and 1970-1-1 |
| setDate() | Sets the date of the Date object |
| setFullYear() | Sets the year value in a Date object |
| setHours() | Sets the hours value in a Date object |
| setMilliseconds() | Sets the milliseconds value in a Date object |
| setMinutes() | Sets the minutess value in a Date object |
| setMonth() | Sets the month value in a Date object |
| setSeconds() | Sets the seconds value in a Date object |
| setTime() | Sets the time value (milliseconds) in a Date object |
| setUTCDate() | Sets the UTC date of a Date object |
| setUTCFullYear() | Sets the UTC year value in a Date object |
| setUTCHours() | Sets the UTC hours value in a Date object |
| setUTCMilliseconds() | Sets the UTC milliseconds value in a Date object |
| setUTCMinutes() | Sets the UTC minutess value in a Date object |
| setUTCMonth() | Sets the UTC month value in a Date object |
| setUTCSeconds() | Sets the UTC seconds value in a Date object |
| setYear() | Sets the year value of a Date object |
| toDateString() | Returns a date as a string value |
| toGMTString() | String value of a Date objects GMT time |
| toLocaleDateString() | Returns a date as a string value |
| toLocaleString() | String value of a Date object, in local time format |
| toLocaleTimeString() | Returns a time as a string value |
| toSource() | String representing the source code of the object |
| toString() | String representation of a Date object |
| toTimeString() | Returns a time as a string value |
| toUTCString() | Date converted to string using UTC |
| UTC() | Milliseconds since 1970 using UTC time |
| valueOf() | Milliseconds since 1970-1-1 |
| constructor() | Reference to the function that created an object |
| prototype() | Creates a new method for Date objects |
var myDate=new Date();
alert('Current date and time is: '+myDate.toLocaleString());
| Method | Usage |
| Object | Provides functionality common to all JavaScript objects |
| toLocaleString() | String value of an object, in local value format |
| toSource() | Object literal representing the specified object |
| toString() | Returns a string representing the object |
| unwatch() | Removes a watchpoint set with the watch method |
| valueOf() | Primitive value of the specified object |
| watch() | Runs a function when specific property is assigned value |
| constructor | Reference to the function that created an object |
| prototype | Creates a new method for Number objects |
| apply() | Applies a method of another object to the current object |
| call() | Executes method of another object on current object |
| toSource() | String representing the source code of the function |
| toString() | String representing the source code of the function |
| valueOf() | String representing the source code of the function |
| arguments() | An array with the arguments passed to a function |
| arguments.callee() | The function body of the currently executing function |
| arguments.length() | Number of arguments passed to the function |
| caller | Reference to the function that created an object |
| constructor() | Reference to the function that created an object |
| length() | Number of arguments expected by the function |
| prototype() | Creates a new method for Function objects |
var username = 'webtrickshome'; alert (username.length);
| Method | Usage |
| decodeURI() | Decodes a URI |
| decodeURIComponent() | Decodes an encoded URI component |
| encodeURI() | Encodes a text string as a URI |
| encodeURIComponent() | Encodes a text string as a component of a URI |
| escape() | Encodes Strings so they can be read on all computers |
| eval() | Evaluates string and executes it as if it was script code |
| isFinite() | Determines whether a value is a finite number |
| isNaN() | Evaluates an argument to determine if it is not a number |
| parseFloat() | Parses a string and returns a floating point number |
| parseInt() | Parses a string and returns an integer |
| unescape() | Decodes String objects encoded with the escape method |
| Infinity | Returns an initial value of Number |
| NaN | Returns NaN indicating that an expression is not a number |
| undefined | Returns value of undefined |
var x = "This is a string"; alert(escape(x));
| Method | Usage |
| abs() | Returns the absolute value of a number |
| acos() | Returns the arccosine (in radians) of a number |
| asin() | Returns the arcsine (in radians) of a number |
| atan() | Returns the arctangent (in radians) of a number |
| atan2() | Returns the arctangent of the quotient of its arguments |
| ceil() | Returns the smallest integer greater than or equal to a number |
| cos() | Returns the cosine of a number |
| exp() | Returns e (the base of natural logarithms) raised to a power |
| floor() | Returns the largest integer less than or equal to a number |
| log() | Returns the natural logarithm (base E) of a number |
| max() | Returns the greater of two numbers |
| min() | Returns the lesser of two numbers |
| pow() | Returns the value of a base expression taken to a specified power |
| random() | Returns a pseudo random number between 0 and 1 |
| round() | Returns the value of a number rounded to the nearest integer |
| sin() | Returns the sine of a number |
| sqrt() | Returns the square root of a number |
| tan() | Returns the tangent of a number |
document.write('The square root of 9 is: '+Math.sqrt(9))
| Method | Usage |
| Number | Object for primitive numeric values |
| toLocaleString() | String value of a Number object, in local value format |
| toString() | Returns a string representing the object |
| valueOf() | The numeric value |
| constructor | Reference to the function that created an object |
| MAX_VALUE | Largest number representable. (~1.79E+308) |
| MIN_VALUE | Smallest number representable. (~5.00E-324) |
| NaN | Special "not a number" value |
| NEGATIVE_INFINITY | Negative infinity, displayed as "-Infinity" |
| POSITIVE_INFINITY | Positive infinity, displayed as "Infinity" |
| prototype | Creates a new method for Number objects |
myDOB = new Number(65);
document.write('I was born in '+myDOB);
| Method | Usage |
| length | Returns the length of the string |
| charAt(n) | Returns the character at the specified position in the string |
| charCodeAt(n) | Returns the character code at the specified position in the string |
| indexOf(string[,n]) | Returns the first position of the substring |
| lastIndexOf(substring[,n]) | Returns the last position of the substring |
| fromCharCode(x[,y,z]) | Constructs a string from the specified sequence of ISO-Latin-1 codeset values |
| substring(x,y) | Returns the specified subset of the string, by specifying the start and end indexes |
| toLowerCase() | Returns the string in all lowercase |
| toUpperCase() | Returns the string in all uppercase |
| split(separator[,n]) | Splits a string into an array of strings by separating the string into substrings |
| slice(x,y) | Does exactly the same as substring |
| substr(x,y) | Returns a subset of a string |
| match | Compare variables |
| replace(/subtext/[gi]) | Replaces substrings of a string |
| search | Searches for substrings in a string |
name = 'webtrickshome';
alert(name.indexOf('b'));
The navigator object contains information about the browser.
| Method | Usage |
| appCodeName | Specifies the code name of the browser |
| appName | Specifies the name of the browser |
| appVersion | Specifies version information for the browser |
| userAgent | Specifies the user agent header |
| mimeTypes | An array of all MIME types supported by the visitors browser |
| plugins | An array of all plug-ins currently installed on the visitors browser |
| javaEnabled | Tests whether Java is enabled |
| plugins.refresh | Makes newly installed plug-ins available and can reload windows containing plug-ins |
| taintEnabled | Specifies whether data tainting is enabled |
| platform | Indicates the platform (Win32, Unix, etc.) for which the browser was compiled |
| language | Indicates the language version of the browser |
| preference | Allows a signed script to get and set certain Navigator preferences |
name = navigator.appName; alert(name);
The window method is the top level method in Javascript. It can represent either a top level window or a frame inside a frameset.
| Method | Usage |
|---|---|
| onDragDrop | Triggered when a user drops an object,such as a file, onto the browser window |
| onLoad | Triggered when a browser finishes loading a window or all of the frames within a FRAMESET tag |
| onMove | Triggered when a user or script moves a window or frame |
| onResize | Triggered when a user or script resizes a window or frame |
| onUnload | Triggered when a user exits a document |
| onBlur | Triggered when a form element loses focus or when a window or frame loses focus |
| onError | Triggered when the loading of a document or image causes an error |
| onFocus | Triggered when a window, frame, or frameset receives focus or when a form element receives input focus |
| defaultStatus | Reflects the default message displayed in the window's status bar |
| document | Contains information on the current document, and provides methods for displaying HTML output to the user |
| frames | An array reflecting all the frames in a window |
| length | The number of frames in the window |
| location | Contains information on the current URL |
| name | A unique name used to refer to the window |
| parent | A synonym for a window or frame whose frameset contains the current frame |
| self | A synonym for the current window |
| status | Specifies a priority or transient message in the window's status bar |
| top | A synonym for the top most browser window |
| window | A synonym for the current window |
| alert | Displays an Alert dialog box with a message and an OK button |
| clearTimeout | Cancels a timeout that was set with the setTimeout method |
| close | Closes the specified window |
| confirm | Displays a Confirm dialog box with the specified message and OK and Cancel buttons |
| open | Opens a new web browser window |
| Prints the contents of the window or frame | |
| prompt | Displays a Prompt dialog box with a message and an input field |
| setTimeout | Evaluates an expression or calls a function once after a specified number of milliseconds has elapsed |
| closed | Specifies whether a window has been closed |
| history | Contains information on the URLs that the client has visited within a window |
| opener | Specifies the window name of the calling document when a window is opened using the open method |
| blur | Removes focus from the specified object |
| focus | Gives focus to the specified object |
| scroll | Scrolls a window to a specified coordinate |
| innerHeight | Specifies the vertical dimension, in pixels, of the window's content area |
| innerWidth | Specifies the horizontal dimension, in pixels, of the window's content area |
| outerHeight | Specifies the vertical dimension, in pixels, of the window's outside boundary |
| outerWidth | Specifies the horizontal dimension, in pixels, of the window's outside boundary |
| pageXOffset | Provides the current x-position, in pixels, of a window's viewed page |
| pageYOffset | Provides the current y-position, in pixels, of a window's viewed page |
| personalbar | Represents the browser window's personal bar (also called the directories bar) |
| scrollbars | Represents the browser window's scroll bars |
| statusbar | Represents the browser window's status bar |
| toolbar | Represents the browser window's tool bar |
| back | Undoes the last history step in any frame within the top level window |
| captureEvents | Sets the window or document to capture all events of the specified type |
| clearInterval | Cancels a timeout that was set with the setInterval method |
| disableExternalCapture | Disables external event capturing set by the enableExternalCapture method |
| enableExternalCapture | Allows a window with frames to capture events in pages loaded from different locations (servers) |
| find | Finds the specified text string in the contents of the specified window |
| forward | Loads the next URL in the history list |
| handleEvent | Invokes the handler for the specified event |
| home | Points the browser to the URL specified in preferences as the user's home page |
| locationbar | Represents the browser window's location bar |
| menubar | Represents the browser window's menu bar |
| moveBy | Moves the window by the specified amounts |
| moveTo | Moves the top left corner of the window to the specified screen coordinates |
| releaseEvents | Sets the window to release captured events of the specified type, sending the event to objects further along the event hierarchy |
| resizeBy | Resizes an entire window by moving the window's bottom right corner by the specified amount |
| resizeTo | Resizes an entire window to the specified outer height and width |
| routeEvent | Passes a captured event along the normal event hierarchy |
| scrollBy | Scrolls the viewing area of a window by the specified amount |
| scrollTo | Scrolls the viewing area of the window to the specified coordinates, such that the specified point becomes the top left corner |
| setInterval | Evaluates an expression or calls a function every time a specified number of milliseconds elapses |
| stop | Stops the current download |
<body onload="return myFunction()">
<script>
function myFunction(){
document.write('Hello World!');
}
</script>
</body>
The window.location object contains information on the current URL. It represents the complete URL of a document and each property of the location object represents a different portion of the URL.
| Method | Usage |
|---|---|
| hash | Specifies an anchor name in the URL |
| host | Specifies the host and domain name, or IP address, of a network host |
| hostname | Specifies the host:port portion of the URL |
| href | Specifies the entire URL |
| pathname | Specifies the URL path portion of the URL |
| port | Specifies the communications port that the server uses |
| protocol | Specifies the beginning of the URL, including the colon |
| search | Specifies a query |
| reload | Forces a reload of the window's current document |
| replace | Loads the specified URL over the current history entry |
var url = window.location.href; alert(url);
The window.history object contains an array of information on the URLs that the client has visited within a window.
| Method | Usage |
|---|---|
| length | Returns number of entries in the history list |
| back | Loads the previous URL in the history list |
| forward | Loads the next URL in the history list |
| go | Loads a URL from the history list |
| next | Specifies the URL of the next history entry |
| previous | Specifies the URL of the previous history entry |
| current | Specifies the URL of the current history entry |
var url = window.history.length; alert(url);
The window.document object contains information about the current document and provides methods for displaying HTML output to the user.
| Method | Usage |
|---|---|
| onClick | An object on a form is clicked |
| onDblClick | The user double clicks a form element or a link |
| onKeyDown | The user depresses a key |
| onKeyPress | The user presses or holds down a key |
| onKeyUp | The user releases a key |
| onMouseDown | The user depresses a mouse button |
| onMouseUp | The user releases a mouse button |
| alinkColor | A string that specifies the ALINK attribute |
| anchors | An array containing an entry for each anchor in the document |
| bgColor | A string that specifies the BGCOLOR attribute |
| cookie | Specifies a cookie |
| fgColor | A string that specifies the TEXT attribute |
| lastModified | A string that specifies the date the document was last modified |
| linkColor | A string that specifies the LINK attribute |
| links | An array containing an entry for each link in the document |
| referrer | A string that specifies the URL of the calling document |
| title | A string that specifies the contents of the TITLE tag |
| URL | A string that specifies the complete URL of a document |
| vlinkColor | A string that specifies the VLINK attribute |
| close | Closes an output stream and forces data to display |
| open | Opens a stream to collect the output of write or writeln methods |
| write | Writes one or more HTML expressions to a document in the specified window |
| writeln | Writes one or more HTML expressions to a document in the specified window and follows them with a newline character |
| applets | An array containing an entry for each applet in the document |
| domain | Specifies the domain name of the server that served a document |
| embeds | An array containing an entry for each plug-in in the document |
| formName | A separate property for each named form in the document |
| forms | An array a containing an entry for each form in the document |
| images | An array containing an entry for each image in the document |
| plugins | An array containing an entry for each plug-in in the document |
| layers | Array containing an entry for each layer within the document |
| captureEvents | Sets the document to capture all events of the specified type |
| getSelection | Returns a string containing the text of the current selection |
| handleEvent | Invokes the handler for the specified event |
| releaseEvents | Sets the window or document to release captured events of the specified type, sending the event to objects further along the event hierarchy |
| routeEvent | Passes a captured event along the normal event hierarchy |
var date = document.lastModified; document.write(date);
Leave a comment