Ruby's Gsub method usage

Hi, This is Shubham Mishra a ROR, iOS, Python developer,  this is the part of Ruby on Rails exploration journey.  In this post we will discuss about the Awesome ways to use ruby's Gsub method.

Now, lets first understand the term 'gsub' -> 'sub': Substitute,  'g': global
Sounds a little odd, no problem lets go practically for better understanding.

Lets say we have a string,  str = "Awesome season"

What we want is to replace a word with another in ruby, say in our case it is replacing season with movie,
now what we will do is,

This is saying:
Replace all the occurrences of the first word 'season' with the 'movie'
Well other than just replacement task your gsub method can do a lot more stuffs, let's have a watch.

Replace pattern with regular expression:
So now lets learn to replace not only a single word but a sentences matching a regular expression, such as matching a phone number, email address etc
The first option is the regex (regular expression), that is a pattern matching language
In our case '\d' looks for the numbers, like '2' and '1' in above string.

Switch pattern with regular expression by gsub of ruby:
This worked with the help of 'Capture Groups', in this case we can use the groups as '\1' the first group, and '\2' for the second group. 
Note it that groups in the regex are created by parentheses.

Pass blocks with gsub in ruby:
We all know that how blocks are an important concept and how it reduces our extra work. So why not to use it for gsub, 

We find the course with '\w+', which means one or more alphabetics characters. The logic is self explanatory as you are reading this blog its mean no need to explain the block logic.

Replace a couple of words with another words using hash with gsub in ruby:
Sometimes we want to replace a character with in a string for different characters. Why not to define the replace relation first and then apply gsub once only with the relation for efficient work.

Lets say, we want to replace 'D' with 'dog', 'C' with 'cat' in a string,

As you can also practice above: https://rextester.com/GCCF90557

Ok great, we are done with this post,  

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