Regular Expressions Taster

Gilbert Hadley Dec 12, 2005
Grab these regular expressions to use in your own JavaScripts. They can add another dimension to your programming experience.
1. Remove white space from both ends of a string.
string = string.replace(new RegExp(/^\s+/),""); // START
string = string.replace(new RegExp(/\s+$/),""); // END


2. Remove white space from ends then 'http://' from the start.
string = string.replace(new RegExp(/^http:\/\//i),"");


3. Remove white space from ends then 'www.' from the start.
string = string.replace(new RegExp(/^www\./i),"");


4. Remove white space from ends then any trailing forward slash.
string = string.replace(new RegExp(/\/$/),"");


5. Remove white space from ends then split the string at first forward slash.
string = string.split(new RegExp(/\//),1);


6. Remove white space from ends then replace back slashes with forward slashes.
string = string.replace(new RegExp(/\\/g),"/");


7. Test for a match at end of string against a number of different options.
 
var domainName =
javascriptsource.com javascriptsource.us
javascriptsource.web javascriptsource.ca
javascriptsource.net javascriptsource.co.uk
javascriptsource.info   javascriptsource.au 


if (domainName.match(/\.com$|\.net$|\.us$|\.co\.uk$/i)) {
  return(true);
} else {
  return(false);
}
result ...

Note: In the context of this demonstration the term 'white space' includes any non-printing character, that is any character you cannot see. Examples include blank spaces, carriage returns, line feeds, tab characters, etc.

RegExp: A regular expression object contains the pattern of a regular expression. It has properties and methods for using that regular expression to find and replace matches in strings or to match patterns in strings. JavaScript RegExp can be used in the following JavaScript String Methods: string.match(), string.search(), string.replace() and string.split().

 

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