diff options
Diffstat (limited to 'doc/syntax/control_expressions.rdoc')
| -rw-r--r-- | doc/syntax/control_expressions.rdoc | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/doc/syntax/control_expressions.rdoc b/doc/syntax/control_expressions.rdoc index f7e6d54924..e91b03e72d 100644 --- a/doc/syntax/control_expressions.rdoc +++ b/doc/syntax/control_expressions.rdoc @@ -232,7 +232,7 @@ You may use +then+ after the +when+ condition. This is most frequently used to place the body of the +when+ on a single line. case a - when 1, 2 then puts "a is one or two + when 1, 2 then puts "a is one or two" when 3 then puts "a is three" else puts "I don't know what a is" end @@ -255,6 +255,20 @@ Again, the +then+ and +else+ are optional. The result value of a +case+ expression is the last value executed in the expression. +Since Ruby 2.7, +case+ expressions also provide a more powerful experimental +pattern matching feature via the +in+ keyword: + + case {a: 1, b: 2, c: 3} + in a: Integer => m + "matched: #{m}" + else + "not matched" + end + # => "matched: 1" + +The pattern matching syntax is described on +{its own page}[rdoc-ref:syntax/pattern_matching.rdoc]. + == +while+ Loop The +while+ loop executes while a condition is true: |