In USA the phone numbers follow a pattern. The pattern is like this.
When we ask user to enter their phone number they can enter their phone number in following ways.
- 786 345 9876
All of the above are not matching with the format in which we want the data. Regular expression can help enforce a particular pattern. If the pattern is not matching then using regular expression we can reject that data.
A regular expression starts with
/ and ends with
Following is a regular expression.
/d has a special meaning. It stands for any digit.
Let’s try to make use of it.
Let’s say that we want to check if a number is a three digit number or not. This is what we can do.
Ruby allows us to use
=~ to check if a regular expression is matching with the word
Let’s see one more example. This time we want to see if zipcode 76981 is of five digits or not.