String Example – Data Type – JavaScript Syntax – JS String Example
String Example – Data Type – JavaScript Syntax – JS String Example
Purpose: – Illustrates the JavaScript syntax for the String Object .
JavaScript String Examples
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Prerequistes:
- Install Visual Web Developer 2008
Syntax: var myStr = new String(“text”); or var myString = “text”; – Demonstrates how to use properties and methods of String object.
Restrictions: None
Notes:
- You can build your own library of syntax examples by using same web site over and over and just add new files to it.
Instructions:
- Use Visual Web Developer 2008
- Create new web site;
- Click File/New Web Site
- Select ASP.NET Website Template
- Select C-Sharp for Language
- name of Web Site could be JavaScript_Syntax.
- Add New folder named “DataType”
- Right-click project name in solution explorer;
- add new folder;
- name of folder should be: DataType
- Add HTML Page Named String to DataType folder
- Right-click DataType folder;
- add new item;
- Select HTML Page
- HTML Page name should be String
- Click on copy code in code below to copy code into HTML Page String.htm
- Right-click on HTML page String and select view in browser
< !DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>String</title>
<script type="text/javascript" >
//*****************************************************
// String Object
//*****************************************************
// NOTE: String Objects are used to store and manipulate
// text
//*****************************************************
// GENERAL SYNTAX:
// var myStr = new String("text");
// Or Simply:
// var myString = "text";
//*****************************************************
// *** String Object Properties ***
//*****************************************************
document.write("***String Object Properties***");
document.write("<br />");
// Property Description
// constructor Returns the function that created the String object's prototype
var myStr = "This is a string";
document.write("myStr.constructor: " + myStr.constructor); // output: function String() { [native code] }
document.write("<br />");
// length Returns the length of the string
document.write("myStr.length: " + myStr.length); // output: 16
document.write("<br />");
// prototype Allows you to add properties and methods to an object
// prototype is available for most objects
// Syntax: object.prototype.name=value
function car(make, model, year) {
this.make = make;
this.model = model;
this.year = year;
}
var myCar = new car("Toyota", "Corolla", 2002);
car.prototype.cost = null;
myCar.cost = 20000;
document.write("myCar.cost: " + myCar.cost);
document.write("<br />");
//*****************************************************
// *** String HTML Wrapper Methods ***
// HTML wrapper methods return the string enclosed in the appropriate
// HTML tags
//*****************************************************
document.write("***String HTML Wrapper Methods***");
document.write("<br />");
// Method Description
// anchor() Creates an anchor
// Syntax: string.anchor(name) - name is required - it is the name of the anchor
var strName = "Hyperlink"; // this will be text of hyperlink
alert(strName.anchor("Hyper")); // this will be anchor
// string.big() Wraps string in <big> tags
var strBig = "Big"
document.write("strBig.big(): " + strBig.big() + "<br />");
// string.blink() Wraps string in <blink> tags
var strBlink = "blink - only works in Firefox & Opera"
document.write("strBlink.blink(): " + strBlink.blink() + "<br />"); // only works
// in Firefox & Opera
// string.bold() Wraps string in <bold> tags
var strBold = "bold"
document.write("strBold.bold(): " + strBold.bold() + "<br />");
// string.fixed() Wraps string in <fixed> tags so that string
// displays in fixed pitch font
var strFixed = "fixed"
document.write("strFixed.fixed(): " + strFixed.fixed() + "<br />");
// string.fontcolor("color") Wraps string in <fontcolor> tags
// The value can be a color name (e.g. green),
// an RGB value (e.g. rgb(0,255,0)),
// or a hex number (e.g. #00FF00)
var strfontcolor = "fontcolor"
document.write("strfontcolor.fontcolor(green): " + strfontcolor.fontcolor("green") + "<br />");
// string.fontsize(size) Wraps string in <fontsize> tags so that string
// displays in fontsize - size is required and can be from 1-7
var strfontsize = "fontsize"
document.write("strfontsize.fontsize(7): " + strfontsize.fontsize(7) + "<br />");
// string.italics() Wraps string in <italics> tags
var stritalics = "italics"
document.write("stritalics.italics(): " + stritalics.italics() + "<br />");
// link() Creates an link
// Syntax: string.link(url) - url is required - it is the url of the link
// The method returns a string wrapped in <a> tags: </a><a href="link">string</a>
var strLink = "Ideal Programmer"; // this will be text of hyperlink
alert(strLink.link("http://idealprogrammer.com")); // this will be link
// string.small() Wraps string in <small> tags - displays string in small font
var strSmall = "Small"
document.write("strSmall.small(): " + strSmall.small() + "<br />");
// string.strike() Wraps string in <strike> tags - displays string in strkethrough font
var strStrike = "Strike"
document.write("strStrike.strike(): " + strStrike.strike() + "<br />");
// string.sub() Wraps string in <sub> tags - displays string in subscript font
var strSub = "Subscript"
document.write("strSub.sub(): " + strSub.sub() + "<br />");
// string.sup() Wraps string in <sup> tags - displays string in superscript font
var strSuperscript = "Superscript"
document.write("strSuperscript.sup(): " + strSuperscript.sup() + "<br />");
//*****************************************************
// *** String Object Methods ***
//*****************************************************
// Method Description
// charAt(index) Returns the character at the specified index - index is required
// 0 is the first character and the last character in a string is string.length-1
var strCharAt = "This is a string.";
document.write("strCharAt(0): " + strCharAt.charAt(0) + "<br />");
document.write("strCharAt.charAt(strCharAt.length - 1): " + strCharAt.charAt(strCharAt.length - 1));
// charCodeAt(index) Returns the Unicode of the character at the specified index
var strcharCodeAt = "This is a string.";
document.write("strcharCodeAt(0): " + strcharCodeAt.charCodeAt(0) + "<br />");
document.write("strcharCodeAt.charCodeAt(strcharCodeAt.length - 1): " + strcharCodeAt.charCodeAt(strcharCodeAt.length - 1) + "<br />");
// concat() Joins two or more strings, and returns a copy of the joined strings
// SYNTAX: string.concat(string2, string3, ..., stringX)
var strA = "Aeschylus ";
var strB = "was a Greek playwright.<br />";
document.write(strA.concat(strB));
// fromCharCode() Converts Unicode values to characters
// SYNTAX: String.fromCharCode(n1, n2, ..., nX) - This is a static method
// The syntax is String.fromCharCode() and not str.fromCharCode
document.write(String.fromCharCode(73, 68, 77, 75, 77));
// indexOf() Returns the position of the first found occurrence of a specified value in a string
// SYNTAX: string.indexOf(searchstring, start) - start is optional
var strIndexOf = "Einstein was a philosophical realist";
document.write("strIndexOf.indexOf(ein): " + strIndexOf.indexOf("ein") + "<br />");
document.write("strIndexOf.indexOf(philo): " + strIndexOf.indexOf("philo") + "<br />");
document.write("strIndexOf.indexOf(real): " + strIndexOf.indexOf("real") + "<br />");
// lastIndexOf() Returns the position of the last found occurrence of a specified value in a string
// SYNTAX: string.lastIndexOf(searchstring, start) - start is optional
var strlastIndexOf = "Einstein was a philosophical realist";
document.write("strlastIndexOf.lastIndexOf(ein): " + strlastIndexOf.lastIndexOf("ein") + "<br />");
document.write("strlastIndexOf.lastIndexOf(philo): " + strlastIndexOf.lastIndexOf("philo") + "<br />");
document.write("strlastIndexOf.lastIndexOf(l): " + strlastIndexOf.lastIndexOf("l") + "<br />");
// match() Searches for a match between a regular expression and a string, and returns the matches
var strMatch = "Einstein defined Morality as giving much and taking very little";
var pattern = /ein/gi;
document.write("strMatch.match(pattern): " + strMatch.match(pattern) + "<br />");
// replace() Searches for a match between a substring (or regular expression) and a string, and replaces the matched substring with a new substring
// SYNTAX: string.Replace("regexp or oldstring", "newstring")
var strReplace = "Ptolemy thought the earth was flat";
document.write("strReplace.replace(Ptolemy, The Ancients)" + strReplace.replace("Ptolemy", "The Ancients") + "<br />");
// search() Searches for a match between a regular expression and a string, and returns the position of the match
// SYNTAX: string.search("regexp or string")
var strSearch = "Copernicus said the sun is in the center.";
document.write("strSearch.search(sun): " + strSearch.search("sun") + "<br />");
// slice() Extracts a part of a string and returns a new string
// SYNTAX: string.slice(beginIndex,endIndex) - endIndex is optional
var strSlice = "Copernicus said the sun is in the center.";
document.write("strSlice.slice(0): " + strSlice.slice(0) + "<br />");
var strSliceA = "Copernicus said the sun is in the center.";
document.write("strSliceA.slice(7,20): " + strSliceA.slice(7,20) + "<br />");
// split() Splits a string into an array of substrings
// SYNTAX: string.split(separator,limit)
// separator is the character(s) that define where split occurs
// limit is optional and defines max number of strings to return
var strSplit = "Copernicus said the sun is in the center.";
document.write("strSplit.split( ): " + strSplit.split(" ") + "<br />");
var strSplitA = "Copernicus said the sun is in the center.";
document.write("strSplitA.split( ,3): " + strSplitA.split(" ",3) + "<br />");
// substr() Extracts the characters from a string, beginning at a specified start position, and through the specified number of character
// SYNTAX: string.substr(startIndex,EndIndex) - EndIndex is optional
var strSubstr = "Newton believed in action at a distance.";
document.write("strSubstr.substr(0,15): " + strSubstr.substr(0, 15) + "<br />");
// substring() Extracts the characters from a string, between two specified indices
// SYNTAX: string.substr(fromIndex,ToIndex) - toIndex is optional and is not included
// in the returned string
var strSubstring = "Newton believed in action at a distance.";
document.write("strSubstring.substring(0,15): " + strSubstring.substring(0, 15) + "<br />");
// toLowerCase() Converts a string to lowercase letters
var strToLowerCase = "Einstein believed space and time are not rigid and linear.";
document.write("strToLowerCase.toLowerCase(): " + strToLowerCase.toLowerCase() + "<br />");
// toUpperCase() Converts a string to Uppercase letters
var strToUpperCase = "Einstein believed space and time are not rigid and linear.";
document.write("strToUpperCase.toUpperCase(): " + strToLowerCase.toUpperCase() + "<br />");
// valueOf() Returns the primitive value of a String object
var strValueOf = "Einstein believed space and time are not rigid and linear.";
document.write("strValueOf.valueOf(): " + strValueOf.valueOf() + "<br />");
</sup></sub></strike></small></italics></fontsize></fontcolor></fixed></bold></blink></big></script>
</head>
<body>
</body>
</html> |
