CoffeeScript replaces substrings

Replace substrings

Problem

You need to replace part of the string with another value.

Solution

Use JavaScript's replace method. It matches a given string and returns the edited string.

The first version requires two parameters: pattern and string replacement

"JavaScript is my favorite!".replace /Java/, "Coffee"
# => 'CoffeeScript is my favorite!'

"foo bar baz".replace /ba./, "foo"
# => 'foo foo baz'

"foo bar baz".replace /ba./g, "foo"
# => 'foo foo foo'

The second version requires two parameters: the pattern and the callback function

"CoffeeScript is my favorite!".replace /(\w+)/g, (match) ->
  match.toUpperCase()
# => 'COFFEESCRIPT IS MY FAVORITE!'

Each match requires a callback function to be called, and the matching value is passed to the callback function as an argument.

Discuss

Regular expressions are a powerful way to match and replace strings.