Strings

Enumerable – see all at Ruby Doc: String

• .count => returns the number of characters
• .include? ‘sub’ => returns true/false if sub found
• .scan(/regexp/) => returns array of array with all occurrences found
• .split (/pattern/)=> returns array of sub strings, with whitespaces
• .sub(/regexp/, replacement s) => replaces first occurrence, returns string
• .gsub => replaces all occurrences, returns string
• .match (/pattern/, pos) . captures =>search from  pos returns matchData
  .char => converts into an array of characters
• .slice(arg) => arg can be integer, range, regexp, string – returns sub string or nil
• .slice!(arg) => returns deleted part
• .capitalize, .downcase, .uppercase, .swapcase: manipulate case
• .center (n), .ljuts, .rjust=> adds whitespace like padding
  .replace(scalc) =>replace a string with a string  already calculated

Examples

Slice a string to isolate the part of interest:

a = "hello hello my dear"
>> a.slice(-7,8)
=> "my dear"

Split a string using regular expressions patterns:

We are given a string with multiple records of interest. Let’s split each substring using a pattern.

Regular expression pattern:

s="There is an extra space  here. A change of line as well. \nThird line here."

s.sub(/\s{2}/, ' ') #replace 2 spaces by one.
s.gsub(/\n/, '')