nested_something : nested_something_else) : something_else # good if some_condition nested_condition ? nested_something : nested_something_else else something_else end Avoid multiple conditions in ternaries. Ternaries are best used with single conditions. [link] Avoid multi-line ?: (the ...
The switch statement is used where you have multiple options. It is similar to elsif statement but it is more preferable thanelsif.whenkeyword is used to check the conditions and whichever comes out to be true, the statements under it executes. Syntax case (variable name) when (condition) #...
For windows you can download Ruby fromhttp://rubyforge.org/frs/?group_id=167 for Linux tryhttp://www.rpmfind.net. Our first program(从此开始) Enter the following into the file, "test.rb". 1 puts"Howdy!" At the C: prompt enter, 1 C:>ruby test.rb This produces: 1 Howdy! OK, d...
Parallel Assignment(交换参数) You can swap the values in variables without the use of a temp variable. Remember your first programming class: Swap the values in "i" and "j"? You had to use a "t" variable to store one of the values first. Not needed in Ruby. 1 2 3 4 5 i =0 ...
Avoid multiple conditions in ternaries. Ternaries are best used with single conditions. [link] Avoid multi-line ?: (the ternary operator), use if/then/else/end instead. [link] # bad some_really_long_condition_that_might_make_you_want_to_split_lines ? something : something_else # good...
Ruby allows you to supply multiple values to a when statement rather than just one e.g.: ruby print "Enter your grade: " grade = gets.chomp case grade when "A", "B" puts 'You pretty smart!' when "C", "D" puts 'You pretty dumb!!' else puts "You can't even use a computer...
In the rest of this document we're going to assume that the reader will be usingphusion/passenger-full, unless otherwise stated. Simply substitute the name if you wish to use another image. Inspecting the image To look around in the image, run: ...
In other words, if we had an if condition statement that evaluated 0, Ruby should choose the true branch or the false branch. This is what we mean by "truthy." If a variable is "truthy," it means it doesn't contain a direct true value but will be treated as true for the purposes...
Prefer if/else constructs in these cases.[link] # bad some_condition ? (nested_condition ? nested_something : nested_something_else) : something_else # good if some_condition nested_condition ? nested_something : nested_something_else else something_else end Avoid multiple conditions in tern...
Pattern matching in Ruby is done through acasestatement. However, instead of using the usualwhen, the keywordinis used instead. It also supports the use ofiforunlessstatements: case[variableorexpression]in[pattern] ...in[pattern]if[expression] ...else...end ...