Finding Substrings Problem You need to find the first or last occurrence of a search string within a message. Solution Use Javascript’s indexOf() and lastIndexOf() to find the first and last occurrences of a string, respectively. Syntax: string.indexOf searchstring, start message = "This is a test string. This has a repeat or two. This might even have a third." message.indexOf "This", 0 # => 0 # Modifying the start parameter message.indexOf "This", 5 # => 23 message.lastIndexOf "This" # => 49 # Count occurrences of a given string message.split(" a ").length - 1 # => 3