`tr` vs `gsub`
- Use
trwhen we want to replace single characters
tr will matches on single characters (not via a regular expression),
therefore the characters don’t need to occur in the same order in the first
string argument.
'abcde'.tr('bda', '123')
#=> "31c2e"
'abcde'.tr('bcd', '123')
#=> "a123e"- Use
gsubwhen we want to replace longer substrings or when we want to use regular expression.
'abcde'.gsub(/bda/, '123')
#=> "abcde"
'abcde'.gsub(/b.d/, '123')
#=> "a123e"