JavaScript: RegExp and Boolean Object

[Ivann]

I have recently began studying JavaScript. I have earlier never studied any programming language. Its only now that I am studying HTML and JavaScript from that last one month. And I have to confess that it is not easy for me at all. I want to know about the JavaScript objects: RegExp Object and Boolean Object. Can any one explain to me in detail about these objects with examples as well.

[Zecho]

An abbreviation for Regular Expression is RegExp. This is useful for searching patterns in textboxes. You can specify the pattern you are searching for in the textbox. For this you have use RegExp IS this pattern. A single character is the simplest pattern. A more detailed pattern may consist of more than one characters and may also include checking for formats and substitutions. Using this you can also provide the characters to be searched from within a given string.

[MindSpace]

The keyword new is used for defining the Regular expression object- RegExp. It stores the search pattern specified. Here is how you define a RegExp object.

var pat=new RegExp("n");

The above code line will locate for the presence of letter n in RegExp object: pat. This object is used to find a given character or set of characters from the values in a textbox.

[Katty]

There are three methods which are contained in the J-Script RegExp Object. They are:

• exec().
• test().
• compile().

If you want to find a string pattern in a specified value and return it then you may use the exec() method which will give a null value if the string pattern is not found.
If you want to just want to locate a string pattern from a given value than the test() method is useful. This method will provide false/true values.
If you want to modify the RegExp you may use the compile() method of Regular Expression in J-Script.

[kelfro]

JavaScript allows the conversion of a non-Boolean value to a Boolean value which is either false or true. Here is an example to create a Boolean value in JavaScript:

var Jbool=new Boolean();

Here is how to create a true boolean value object:

var Jbool=new Boolean("Java");
var Jbool=new Boolean(true);

Here is how to create a false boolean value object:

var Jbool=new Boolean(0);
var Jbool=new Boolean(null);
var Jbool=new Boolean("");

[Reegan]

Example for compile() of RegExp:

var srh =new RegExp("w");
document.write(srh.test("World is Beautiful"));
srh.compile("t");
document.write(srh.test("World is Beautiful"));

Example for test() of RegExp:

var srh=new RegExp("f");
document.write(srh.test("World is Beautiful forever"));

JavaScript has a Regular Expressions to match the pattens in a text contained in a text box.