Think about an email address with a ruby regex you can define what a valid email address looks like.
Ruby string regex replace.
Two common use cases for regular expressions include validation parsing.
As is often the case this is best explained through the use of an example.
The sub sub.
A year an email address a phone number etc.
Replacing a single word is fine.
All of these methods perform a search and replace operation using a regexp pattern.
A1 gsub d 2 a2 the first argument is a regular expression and it s too much to cover here.
First you don t declare the type in ruby so you don t need the first string.
Ruby program that uses gsub with regexp value quickly slowly or happily replace all word sending with ly with a string.
Regexp quote your string for example.
Changing a section of a string ruby allows part of a string to be modified through the use of the method.
But it s a pattern matching language.
Replace patterns with a regular expression.
Ruby regular expressions ruby regex for short help you find specific patterns inside strings with the intent of extracting data for further processing.
Ly the lowercase substring ly.
Re regexp new map keys map x regexp escape x join and finally gsub.
Value gsub w ly rep puts value output rep rep or rep regexp pattern w one or more word characters.
In other words your program will be able to tell the difference between a valid invalid email address.
But what if you could replace a pattern.
Will be escaped since it s otherwise interpreted as any character.
Modify the string on which they are called whereas the sub and gsub returns a new string leaving the original unmodified.
Ruby s string scan method of course can be used to find all occurrences of the pattern but i m not sure how to replace the returned occurrences once i ve made the.
To use this method simply pass through the string of characters to be replaced to the method and assign the new string.
S str gsub re m map m you need the regexp escape in there in case anything you want to replace has a special meaning within a regex.
Replaces the first occurrence of the pattern and gsub gsub.
Method isn t a good fit because i need to take the returned occurrence and then manipulate it to come up with the value that will be used to replace it.
Or thanks to steenslag you could use.
