substring replace in ruby

To replace a substring in Ruby, you can use the gsub method. Here are the steps to replace a substring in Ruby:

  1. Initialize a string: Start by initializing a string variable that contains the original string.

  2. Use the gsub method: Call the gsub method on the string variable and pass in two arguments: the substring you want to replace and the replacement string you want to use.

  3. Assign the result: Assign the result of the gsub method to a new variable or overwrite the original string variable with the updated string.

Let's see an example to illustrate these steps:

original_string = "Hello, World!"
updated_string = original_string.gsub("World", "You")

In this example, we initialize the original_string variable with the value "Hello, World!". Then, we call the gsub method on original_string and pass in two arguments: "World" (the substring we want to replace) and "You" (the replacement string). The gsub method replaces all occurrences of the substring with the replacement string. The result is assigned to the updated_string variable.

After executing this code, the value of updated_string will be "Hello, You!".

You can also use regular expressions with the gsub method to replace substrings based on patterns. For example:

original_string = "Hello, World!"
updated_string = original_string.gsub(/o+/, "e")

In this example, we use a regular expression /o+/ as the first argument to gsub. This regular expression matches one or more occurrences of the letter "o". The gsub method replaces all such occurrences with the letter "e". The result is assigned to the updated_string variable.

After executing this code, the value of updated_string will be "Helle, Werld!".

That's how you can replace a substring in Ruby using the gsub method.