Reg Ex

Regular Expressions: 

Regular Expressions In ColdFusion and Studio

Definitions: 

Definitions String - Any collection of 0 or more characters. Example: 'This is a String' SubString - A segment of a String Example: 'is a' Case Sensitivity - detection if a character is upper or lower case.

Simple Task: 

Simple Task Find the word 'Name' inside a string: andlt;CFSET String='My name is Michael Dinowitz'andgt; andlt;CFOUTPUTandgt; Position=#Find(‘Name’, String)# andlt;/CFOUTPUTandgt; Position=0

Slide4: 

Simple Task Find the word 'Name' inside a string: andlt;CFSET String='My name is Michael Dinowitz'andgt; andlt;CFOUTPUTandgt; Position=#Find(‘name’, String)# andlt;/CFOUTPUTandgt; Position=4

Simple Task: 

Simple Task Find the word 'Name' inside a string: andlt;CFSET String='My name is Michael Dinowitz'andgt; andlt;CFOUTPUTandgt; Position= #FindNoCase(‘Name’, String)# andlt;/CFOUTPUTandgt; Position=4

Simple Task: 

Simple Task Find the word 'Name' inside a string using Regular Expressions: andlt;CFSET String='My name is Michael Dinowitz'andgt; andlt;CFOUTPUTandgt; Position=#REFindNoCase(‘Name’, String)# andlt;/CFOUTPUTandgt; Position=4

Intro to Regular Expressions: 

Intro to Regular Expressions Refereed to as RegEx Matches patterns of characters Used in many languages (ColdFusion, Perl, JavaScript, etc.) Uses a small syntax library to do ‘dynamic’ matches Can be used for Search and/or Replace actions Slightly slower than similar Find() and Replace() functions Has both a case sensitive and a non-case sensitive version of each function operation REFind() REFindNoCase() REReplace() REReplaceNoCase

RegEx Basics: 

RegEx Basics Rule 1: A character matches itself as long as it is not a control character. Example: A='A' A='a' (non-case sensitive) andlt;CFSET String='My name is Michael Dinowitz'andgt; andlt;CFOUTPUTandgt; Position= #REFindNoCase(‘n’, String)# andlt;/CFOUTPUTandgt; Position=4

RegEx Basics: 

RegEx Basics Rule 1a: A search will return the first successful match. To get a different match, set the start position (third attribute of the function - optional) andlt;CFSET String='My name is Michael Dinowitz'andgt; andlt;CFOUTPUTandgt; Position1= #REFindNoCase(‘M’, String)# Position2= #REFindNoCase(‘M’, String, 2)# andlt;/CFOUTPUTandgt; Position1=1 Position2=12

RegEx Basics: 

RegEx Basics Rule 2: A collection of non-control characters matches another collection of non-control characters. AA='AA' AA!='Aa' (case sensitive) AA='Aa' (non-case sensitive) A A='A A' (notice the space) andlt;CFSET String='My name is Michael Dinowitz'andgt; andlt;CFOUTPUTandgt; Position=#REFindNoCase(‘y n’, String)# andlt;/CFOUTPUTandgt; Position=2

RegEx Basics: 

RegEx Basics Rule 3: A period (.) is a control character that matches ANY other character. Example: . = 'A' A. = 'Ac' A.A='A A' andlt;CFSET String='My name is Michael Dinowitz'andgt; andlt;CFOUTPUTandgt; Position= #REFindNoCase(‘N.me’, String)# andlt;/CFOUTPUTandgt; Position=4

RegEx Basics: 

RegEx Basics Rule 4: A control character can be ‘escaped’ by using a backslash (\) before it. This will cause the control character to match a text version of itself. Example: . = '.' \. = '.' A\.A = 'A.A' andlt;CFSET String='My name is Michael Dinowitz.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘tz\.’, String)# andlt;/CFOUTPUTandgt; Position=26

RegEx Anchoring: 

RegEx Anchoring Rule 5a: Using the caret (^) will make sure the text your searching for is at the start of the string. Example: ^A= 'A' ^M != 'AM' andlt;CFSET String='My name is Michael Dinowitz.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘^My’, String)# Position2=#REFindNoCase(‘^is’, String)# andlt;/CFOUTPUTandgt; Position1=1 Position2=0

RegEx Anchoring: 

RegEx Anchoring Rule 5b: Using the dollar sign ($) will make sure the text your searching for is at the end of the string. Example: A$ = 'A' M$ = 'MAM' (second M will be returned) andlt;CFSET String='My name is Michael Dinowitz.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘\.$’, String)# andlt;/CFOUTPUTandgt; Position1=28

RegEx Ranges: 

RegEx Ranges Rule 6: When looking for one of a group of characters, place them inside square brackets ([]). Example: ‘[abc]’ will match either a, b, or c. ‘[.+$^]’ will match either a period (.), a plus (+), a dollar sign ($) or a caret (^). Note that all special characters are escaped within square brackets. andlt;CFSET String='My name is Michael Dinowitz.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘M[aeiou]’, String)# andlt;/CFOUTPUTandgt; Position1=6

RegEx Ranges: 

RegEx Ranges Rule 7a: A caret (^), when used within square brackets ([]) is has the effect of saying ‘NOT these characters’. It must be the first character for this to work. Example: ‘[^abc]’ will match ANY character other than a, b, or c. andlt;CFSET String='My name is Michael Dinowitz.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘M[^aeiou]’, String)# andlt;/CFOUTPUTandgt; Position1=1

RegEx Ranges: 

RegEx Ranges Rule 7b: A dash (-), when used within square brackets ([]) has the effect of saying ‘all characters from the first character till the last’. Example: ‘[a-e]’ will match ANY character between a and e. andlt;CFSET String='My name is Michael Dinowitz.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘M[a-m]’, String)# andlt;/CFOUTPUTandgt; Position1=6

RegEx Ranges: 

RegEx Ranges Rule 8: ColdFusion has a series of pre-built character ranges. These are referenced as [[:range name:]]. Example: [[:digit:]] - same as 0-9 (all numbers) [[:alpha:]] - same as A-Z and a-z (all letters of both case) andlt;CFSET String='My name is Michael Dinowitz.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘[[:space:]]’, String)# andlt;/CFOUTPUTandgt; Position1=3

RegEx Character Classes: 

RegEx Character Classes

RegEx Multipliers: 

RegEx Multipliers Any character or character class can be assigned a multiplier that will define the use of the character or class. These multipliers can say that a character must exist, is optional, may exist for a certain minimum or maximum, etc. Multiplier characters include: Plus (+) One or more Asterisk (*) 0 or more Question Mark (?) may or may not exist once Curly Brackets({}) A specific range of occurances

RegEx Multipliers: 

RegEx Multipliers The Plus (+) multiplier specifies that the character or character group must exist but can exist more than once. Example: A+ - A followed by any number of additional A’s [[:digit:]]+ - A number (0-9) followed by any amount of additional numbers andlt;CFSET String='Mississippi is a hard word.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘is+i’, String)# andlt;/CFOUTPUTandgt; Position1=2

RegEx Multipliers: 

RegEx Multipliers The Asterisk (*) multiplier specifies that the character or character group may or may not exist, and can exist more than once. (I.e. 0 or more) Example: A* - Either no A or an A followed by any number of additional A’s [[:digit:]]* - Either no number (0-9) or a number followed by any amount of additional numbers andlt;CFSET String='Mississippi is a hard word.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘si*s’, String)# andlt;/CFOUTPUTandgt; Position1=3

RegEx Multipliers: 

RegEx Multipliers The Question mark (?) multiplier specifies that the character or character group may or may not exist, but only once. Example: A? - Either A or no As [[:digit:]]+ - One or no numbers (0-9) andlt;CFSET String='Mississippi is a hard word.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘p?i’, String)# andlt;/CFOUTPUTandgt; Position1=2

RegEx Multipliers: 

RegEx Multipliers Curly brackets ({}) can be used to specify a minimum and maximum range for a character to appear. The format is {min, max} Example: A{2,4} - 2 As or more but no more than 4. [[:digit:]]{1,6} - 1 number (0-9) or more, but no more than 6. andlt;CFSET String='Mississippi is a hard word.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘s{2,3}’, String)# andlt;/CFOUTPUTandgt; Position1=3

RegEx SubExpressions: 

RegEx SubExpressions SubExpressions are a way of grouping characters together. This allows us to reference the entire group at once. To group characters together, place them within parenthesis (). Example: (Name) = name (Name)+ = name, namename or basically one or more names. andlt;CFSET String='Mississippi is a hard word.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘(iss)+’, String)# andlt;/CFOUTPUTandgt; Position1=2

RegEx SubExpressions: 

RegEx SubExpressions An additional special character that is usable within a subExpression is the pipe (|). This means either the first group of text or the second (or more). Example: (Na|me) = na or me (Name|Date) = Name or date andlt;CFSET String='Mississippi is a hard word.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘(hard|word)’, String)# andlt;/CFOUTPUTandgt; Position1=18

RegEx SubExpressions: 

RegEx SubExpressions SubExpressions allow us to do something else that’s special; back referencing. This is the ability to reference one or more groups directly. This is done by using the backslash (\) followed by a number that specifies which subexpression we want. Example: (name)\1 = namename (Name|Date)\1 = namename or datedate andlt;CFSET String='Mississippi is is a hard word.'andgt; andlt;CFOUTPUTandgt; Position1=#REFindNoCase(‘(is )\1’, String)# andlt;/CFOUTPUTandgt; Position1=13

REReplace: 

REReplace The REReplace() and REReplaceNoCase() functions use everything you’ve learned about searching and allows you to ‘work’ with the search results, I.e. replace them with something. Example: andlt;CFSET String='Mississippi is a hard word.'andgt; andlt;CFOUTPUTandgt; Position1=#REReplaceNoCase(String, ‘iss’, ‘emm’)# Position2=#REReplaceNoCase(String, ‘iss’, ‘emm’, ‘all’)# andlt;/CFOUTPUTandgt; Position1=Memmissippi is a hard word Position2=Memmemmippi is a hard word