Web Programming Step by Step

Lecture XX
Client-Side Validation

Regular expressions in JavaScript

string.match(regex) if string fits the pattern, returns the matching text; else returns null can be used as a Boolean truthy/falsey test: var name = $("name").value; if (name.match(/[a-z]+/)) { ... }


					an i can be placed after the regex for a case-insensitive match
						
							name.match(/Marty/i) will match "marty", "MaRtY", ...





			
				Replacing text with regular expressions

				
					string.replace(regex, "text")
						
							replaces the first occurrence of given pattern with the given text
							var str = "Marty Stepp";

							str.replace(/[a-z]/, "x") returns "Mxrty Stepp"
							returns the modified string as its result; must be stored

							str = str.replace(/[a-z]/, "x")
						
					

					a g can be placed after the regex for a global match (replace all occurrences)
						
							str.replace(/[a-z]/g, "x") returns "Mxxxx Sxxxx"

						

					

					using a regex as a filter
						
							str = str.replace(/[^A-Z]+/g, "") turns str into "MS"

Web Programming Step by Step, Lecture XX

Client-Side Validation

Web Programming Step by Step

Lecture XX Client-Side Validation

Regular expressions in JavaScript

Replacing text with regular expressions

Lecture XX
Client-Side Validation