http://bucarotechelp.com/design/jsref This section is a JavaScript quick reference. Here you can quicky get information about JavaScript's built-in objects, their methods and properties and about JavaScript's built-in functions, with example code. en-us Wed, 16 May 2012 18:07:04 GMT http://bucarotechelp.com/design/jsref/jsref.xml http://bucarotechelp.com/design/jsref/88070502.asp You should never write code that attempts to access elements on a document before the page completes loading because the element may not be created yet. The onload event allows you to access webpage elements immediately after all the coded elements have been created. Wed, 16 May 2012 18:07:04 GMT http://bucarotechelp.com/design/jsref/88072301.asp As the user surfs the Web, the history object maintains a list of the URLs they visited. The history object has three methods to move through the history list back() forward() and go(). Tue, 08 May 2012 15:18:36 GMT http://bucarotechelp.com/design/jsref/88072403.asp The do/while loop is similar to the while loop except that the while loop evaluates the test condition first before executing the statements, but the do/while executes the statements first, then evaluates the test condition. Mon, 07 May 2012 20:51:31 GMT http://bucarotechelp.com/design/jsref/88072801.asp The Java Script eval function accepts a string argument. If the string is an expression, it evaluates the expression. If the string contains JavaScript statements it executes the statements. Thu, 03 May 2012 18:42:47 GMT http://bucarotechelp.com/design/jsref/88080004.asp Java Script provides three types of message boxes, the alert, confirm, and prompt. They are all easy to create and use. A prompt presents a message, a text box for user input, an [OK] button and a [Cancel] button. Mon, 30 Apr 2012 16:33:38 GMT http://bucarotechelp.com/design/jsref/88080003.asp Java Script provides three types of message boxes, the alert, confirm, and prompt. They are all easy to create and use. A confirm presents a message with an [OK] button and a [Cancel] button. Mon, 30 Apr 2012 16:08:39 GMT http://bucarotechelp.com/design/jsref/88080002.asp Java Script provides three types of message boxes, the alert, confirm, and prompt. They are all easy to create and use. The alert message box presents a message with a single [OK] button to dismiss the message box. Mon, 30 Apr 2012 15:30:36 GMT http://bucarotechelp.com/design/jsref/90001401.asp Maybe yourlayout is such that the user must have a certain screen size, a minimum screen size, or a certain color depth for your webpage to look right. The Screen object gives you that information about the user's sreen. Fri, 17 Dec 2010 18:12:26 GMT http://bucarotechelp.com/design/jsref/90002303.asp An Operator is a charactor or several charactors that cause JavaScript to perform an operation on a value or variable and returns the result of that operation. Wed, 8 Dec 2010 23:22:44 GMT http://bucarotechelp.com/design/jsref/90010802.asp When you load a Web page into your browser, the URL is stored in the window object's location object. You can use location object's assign or replace methods to load a different page into the window. Mon, 22 Nov 2010 22:20:41 GMT http://bucarotechelp.com/design/jsref/90030601.asp The Java Script Conditional Operator uses a question mark (?) and a colon (:) as a short-cut way to create an if/else statement. In good code the conditional statement should be replaced with a simple if/else statement. Fri, 24 Sep 2010 16:28:39 GMT http://bucarotechelp.com/design/jsref/90030702.asp getElementById is a method of the browser document object that lets you access html elements methods in order to execute an element's methods in order to change its properties. This is referred to as Dynamic HTML (DHTML). Thu, 23 Sep 2010 22:49:21 GMT http://bucarotechelp.com/design/jsref/93091802.asp In loops that contain a large block of code, if you know a certain value in an iteration does not require processing by that block of code, you can use the continue statement to skip that code and move on to the next iteration of the loop. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/93092205.asp The break statement provides you with a means of exiting a loop early. The break statement is commonly used to exit a loop when a value has reached or exceeded a set limit, or when searching through an array, when you've found the data for which you were searching. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94001202.asp The document object has several properties that can provide you with information about a webpage's file. The document object's fileCreatedDate, fileModifiedDate, and fileSize properties can be used to determine the date a webpage was created, the date it was last modified, and the size of the webpage file. This example shows how to display these properties. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94001801.asp The document object's fgColor, bgColor, linkColor, alinkColor, and vlinkColor properties can be used to set colors in a webpage interactively. In addition to demonstrating how to set these document properties, this example shows you how to use Java Script to access an html select list in a form and how to use a Java Script switch/case structure. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94010302.asp Java Script 1.5 also provides the encodeURIComponent function, which can be used to encode part of a URI. For example, if you created an identifier containing a slash, neither the escape function nor the encodeURI will encode slashes because they are a legal characters in a URL or URI. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94020701.asp An array is an ordered collection of data, each item of data being identified by an index number. Java Script arrays can contain a variety of data types. Assigning arrays as array elements allows you to create a multidimensional array. Using simple Java Script code you could use a multidimensional array to create a fairly sophisticated database application. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94032201.asp To get access to a specific element on a webpage, assign it a unique id and use the document.getElementById method to get a reference to it. To access all elements of a certain type, use the getElementsByTagName method to create a reference to the collection of all the elements of that type. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94032501.asp The DOM chart provided here shows only part of the DOM. I would have liked to provided a more complete chart, but I can't find an example of a DOM chart that is complete without getting overly complex. I'll be back to update this chart as I learn more. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94040101.asp In Java Script strings, A backslash indicates the next character is part of an escape sequence used to inform the interpreter that special action should be taken. But what if you actually want to include a backslash in a string, not to start an escape sequence, but to just be displayed as a backslash? Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94040301.asp When you display a long text string in an alert box, it creates an unappealing too wide message box. You can improve the aspect ratio of the message box by placing newline (\n) character escape sequences within the string to explicitly define where the string should break to create a new line. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94040802.asp The "while" loop evaluates an expression, and while the expression evaluates to "true", the "while" loop will repeatedly execute a series of statements. The difference between the "while" loop and the "do/while" loop is that the "do/while" loop executes the statements inside the curly brackets one time first before it evaluates the "condition" expression. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94041001.asp A loop structure allows you execute a series of statements over and over. Several kinds of loop structures are available in Java Script, the most common loop is the for loop, which enables you to execute the loop a specific number of times. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94041401.asp The switch/case structure lets you match a variable's or expression's value to a number of values and then execute code when a match is found. A description of the switch/case structure is shown in this article. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94041501.asp The "if" or "if/else" structure can be used to provide flow control in your Java Script code. Flow control determines which statements are executed based upon the results of a test or condition. An "if/else" structure is coded as shown in this article. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94041602.asp Comparison operators compare the values of two variables or statements and return the result of the comparison as either true or false. The result of the comparison can be used to control the flow of the program. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94041702.asp You can include single quotes in a string by enclosing the string in double quotes, or you can include double quotes in a string by enclosing the string in single quotes. In the situation where you need to use more than two levels of quotes, you can escape quote characters by placing a backslash character in front of a quote character. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042101.asp The easiest and most proper way to format a number as a currency value is to use the Java Script Number object's toFixed method. The toFixed method will only work in newer browsers like Internet Explorer version 5.5 and later. If you can't be sure that all your users have newer browsers than you can create your own function to format a number as a currency, as shown here. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042201.asp In many instances, Java Script automatically converts numbers to strings, but you can use the String object constructor or the toString method to explicitly convert a number to a string. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042302.asp The Java Script String object provides several methods that allow us to search for a character or substring within a string. For example, the code below finds the word "easy" in the sentence "code is easy to read". Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042402.asp Java Script provides a built-in string object that provides you with many methods for manipulating strings. It does not contain a built-in method to trim leading and trailing blanks from a string. When you need to compare two stings, use the trimString function provided in this article, along with the toUppercase or toLowercase method to pre-process the stings before testing them with the equality operator. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042701.asp The Java Script Math object provides the trigonometric functions cosine, sine, tangent, along with many others. All the trigonometric functions return an angular value in radians. Why use radians rather than degrees? Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042702.asp In a situations where you need to convert a value stored as a string, for example a value returned from a form element, to a number for use in a calculation, use the Java Script parseInt or parseFloat function. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042703.asp In some situations, for example when you want to display a number, you may want to round it to a certain number of decimal places. The Java Script Math object provides three different methods for rounding numbers. Choose the apropriate method (round, ceil, or floor) for the situation. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042704.asp The absolute value is simply the value without a sign, for example the absolute value of 4, or +4, is the same as the absolute value of -4: 4. If you are creating an application that requires the absolute value of a number, use the Java Script Math.abs method. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042705.asp If you want to compare two numbers in Java Script, you can always use an if-else statement, but the Math object provides two methods that do that for you. The Math.max method returns the highest value, the Math.min method returns the lowest value. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042707.asp Normally a "number" is just a variable that you assigned a numerical value to. But JavaScript provides a Number object that gives you some powerful formatting routines for working with numbers. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042708.asp The Java Script Math object's random method returns a floating-point value between 0 and 1. To generate a random integer between zero and n, use the formula provided here. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94042801.asp Placing the increment or decrement operator in front of the variable means to increment (or decrement) the value first before using it. Placing the increment or decrement operator in after the variable means to use the value first, then increment (or decrement) it. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94072201.asp Reserved words or keywords are words that are part of the JavaScript language and therefor have special meaning in Javascript. These reserved words cannot be used for variable or function names. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/94072302.asp The type of a piece of data is important because it determines what kind of data can be stored in it and what operations can be performed on it. For example, you can multiply the number 2 by the number 3 to get the result 6. But if you multiply the character "2" by the character "3", you get nonsense results. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/95031701.asp The JavaScript Math object gives you powerful routines that let you generate random numbers, convert numbers to strings and strings to numbers, and perform trigonometric functions and much more. After this introduction, you should be able to create some interesting JavaScript applications. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/95100002.asp There are certain situations in Java Script programming where we can run into a problem storing or passing data. Those situations call for the use of the "escape" functions. For example, when storing data in a browser cookie. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/97071830.asp Java Script provides the built-in String object that provides you with many methods for searching and manipulating strings. In this article I will provide you with examples that show you how to use the most important methods of the string object. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/98010521.asp In this article, I show you how to use Java Script to move a window, resize a window, bring a window to the front, and bring a window to the back. This is all very easy to do using the following Java Script methods. Wed, 3 Sep 2008 15:47:28 GMT http://bucarotechelp.com/design/jsref/98011350.asp Cookies are a way of storing information about a user on the users computer. Cookies can be used to track a users visits to and path through a web site, store a users choices, and much more. Wed, 3 Sep 2008 15:47:28 GMT