Introduction:
In this article I am going to explain about string object and what are the methods are available to perform manipulation on string.
String object in Java Script provides us work with a series of characters. The string object is used to manipulate a stored piece of text. String objects are created with the new keyword.
Syntax for creating string object:
var text=new String(“string”);
Or more simply we can declare string object like this
var text=”string”;
String Objects Properties:
Constructor: It will return the function that created the string object prototype.
Length: Returns the length of the string.
Prototype: Allows us to add properties and method to an object.
String Object Methods:
1.charAt () : It will return the character at the specified index.2.charCodeAt() : It will return the number which is the actually the Unicode value of the character at the specified index.3.Concat() : It combine the two string into a single string.4.indexOf() : Returns the index position of the first occurrence of a specified value in a string.5.lastIndexOf() : Returns the last index position of a specified value in a string.6.match() : Used to match a given string with a regular expression.7.toString() : Returns the string representation of a specified object.8.toUpperCase() : Returns the call calling string value to uppercase.9.substring() : Returns a extracted substring between two indexes in the string.10.toLowerCase() : Returns the calling string value to lowercase.11.valueOf() : It returns the primitive value of a specified object.12.Split() : It splits the string object into array of two strings by separating the two strings into substrings.13.search() : To search a given pattern in a string.
String HTML Wrappers:
These are a list of methods which returns copy of the string wrapped inside the appropriate HTML tag.
1.big() : It creates a string which is to be displayed in a big font same as it were in a big tag.
2.blink() : It creates a string which provides the same function as the <blink> tag in that keeps blinking the text contained in tag.
3.bold(): It creates a string as it were in the <b> tag.
4.sub() : It is used to displays the string as a subscript same as the <sub> tag .
5.sup() : It is used to display the string as a superscript same as the <sup> tag.
Example of Length Function in Java Script:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
var countString = "Abhishek";
document.write("Length of the string is : " + countString.length);
</script>
</head>
<body>
</body>
</html>
Output will be: Length of the string is : 8
Example of Split function used in Java Script:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
var myString = "Abhishek";
var mysplit = myString.split("i");
document.write("The first element is " + mysplit[0] + "<br />" );
document.write("The second element is " + mysplit[1]);
</script>
</head>
<body>
</body>
</html>
In this example the split function will break the string into two parts
where the i is encountered Output will be: The first element is Abh,
The second element is shek.
Example of Search Function:
When we have to search that a given expression is available in the given
string. If the match was successful then it will return the position where the
match was found else it will return -1.
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
var myregex = /Monday/;
var myString = "Today is Monday";
var IsMatchPosition = myString.search(myregex);
if (IsMatchPosition != -1) {
document.write("String matched at position " + IsMatchPosition);
}
else {
document.write("String not matched");
}
</script>
</head>
<body>
</body>
</html>
String Replace Function:
String Replace function takes two argument:
1.Search For: Search for contains what word is going to be replaced.
2.Replace Text: It contains the words which will replace the Search for
Content.
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
var day = "Tuesday";
var OldString = "Today is Monday";
document.write("Old String is " + OldString);
var NewString = OldString.replace("Monday", day);
document.write("<br/>New String is " + NewString);
</script>
</head>
</html>
Output is:
Example of IndexOf() Function:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
var str = "is";
var myString = "Today is Monday";
var indexFound = myString.indexOf(str);
document.write(indexFound);
</script>
</head>
<body>
</body>
</html>
In this example I am showing the use of indexOf(), It will show the index
where
the first match is found.
Conclusion: From this article you will know about the string functions
which are available in Java Script and using these functions what
operations can be performed on a given string.
<head>
<script type="text/javascript">
var myString = "Abhishek";
var mysplit = myString.split("i");
document.write("The first element is " + mysplit[0] + "<br />" );
document.write("The second element is " + mysplit[1]);
</script>
</head>
<body>
</body>
</html>
The second element is shek.
<head>
<script type="text/javascript">
var myregex = /Monday/;
var myString = "Today is Monday";
var IsMatchPosition = myString.search(myregex);
if (IsMatchPosition != -1) {
document.write("String matched at position " + IsMatchPosition);
}
else {
document.write("String not matched");
}
</script>
</head>
<body>
</body>
</html>
<head>
<script type="text/javascript">
var day = "Tuesday";
var OldString = "Today is Monday";
document.write("Old String is " + OldString);
var NewString = OldString.replace("Monday", day);
document.write("<br/>New String is " + NewString);
</script>
</head>
</html>
<head>
<script type="text/javascript">
var str = "is";
var myString = "Today is Monday";
var indexFound = myString.indexOf(str);
document.write(indexFound);
</script>
</head>
<body>
</body>
</html>
the first match is found.
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