One line if statement not working
RubyRuby Problem Overview
<%if @item.rigged %>Yes<%else%>No<%end%>
I was thinking of something like this?
if @item.rigged ? "Yes" : "No"
But it doesn't work. Ruby has the ||= but I"m not even sure how to use that thing.
Ruby Solutions
Solution 1 - Ruby
Remove if from if @item.rigged ? "Yes" : "No"
Ternary operator has form condition ? if_true : if_false
Solution 2 - Ruby
In Ruby, the condition and the then part of an if expression must be separated by either an expression separator (i.e. ; or a newline) or the then keyword.
So, all of these would work:
if @item.rigged then 'Yes' else 'No' end
if @item.rigged; 'Yes' else 'No' end
if @item.rigged
'Yes' else 'No' end
There is also a conditional operator in Ruby, but that is completely unnecessary. The conditional operator is needed in C, because it is an operator: in C, if is a statement and thus cannot return a value, so if you want to return a value, you need to use something which can return a value. And the only things in C that can return a value are functions and operators, and since it is impossible to make if a function in C, you need an operator.
In Ruby, however, if is an expression. In fact, everything is an expression in Ruby, so it already can return a value. There is no need for the conditional operator to even exist, let alone use it.
BTW: it is customary to name methods which are used to ask a question with a question mark at the end, like this:
@item.rigged?
This shows another problem with using the conditional operator in Ruby:
@item.rigged? ? 'Yes' : 'No'
It's simply hard to read with the multiple question marks that close to each other.
Solution 3 - Ruby
One line if:
<statement> if <condition>
Your case:
"Yes" if @item.rigged
"No" if !@item.rigged # or: "No" unless @item.rigged
Solution 4 - Ruby
From what I know
3 one-liners
a = 10 if <condition>
example:
a = 10 if true # a = 10
b = 10 if false # b = nil
2. a = 10 unless <condition>
example:
a = 10 unless false # a = 10
b = 10 unless true # b = nil
3. a = <condition> ? <a> : <b>
example:
a = true ? 10 : 100 # a = 10
a = false ? 10 : 100 # a = 100
I hope it helps.
Solution 5 - Ruby
Both the shell and C one-line constructs work (ruby 1.9.3p429):
# Shell format
irb(main):022:0> true && "Yes" || "No"
=> "Yes"
irb(main):023:0> false && "Yes" || "No"
=> "No"
# C format
irb(main):024:0> true ? "Yes" : "No"
=> "Yes"
irb(main):025:0> false ? "Yes" : "No"
=> "No"
Solution 6 - Ruby
if else condition can be covered with ternary operator
@item.rigged? ? 'Yes' : 'No'
Solution 7 - Ruby
For simplicity, If you need to default to some value if nil you can use:
@something.nil? = "No" || "Yes"
Solution 8 - Ruby
You can use:
(@item.rigged) ? "Yes" : "No"
If @item.rigged is true, it will return 'Yes' else it will return 'No'.
Solution 9 - Ruby
if apple_stock > 1
:eat_apple
else
:buy_apple
end
Above statement can written in form of ternerary statement in ruby as:
apple_stock > 1 ? :eat_apple : :buy_apple
Solution 10 - Ruby
Don't forget it can generate the content from the ruby tag:
v
<%= @item.rigged? ? "Yes" : "No" %>
The tick (v) indicates using the equal sign to generate text in the html.