All Questions
172
questions
0
votes
2
answers
85
views
Why does && operator not work inside a hash block but and operator does?
Given the following hash
hash = {a: 5, b: 10}
I want to check if all values are Integers and < 10.
hash.all?{|key,value| value.is_a? Integer && value < 10} ## TypeError: class or module ...
- 638
0
votes
2
answers
84
views
Why is x-- a valid ruby statement but it doesn't do anything?
I know ruby doesn't support integer increment x++ or decrement x-- as C does. But when I use it, it doesn't do anything and doesn't throw an error either. Why?
Edit:
Sorry the code I actually found ...
- 5,012
-1
votes
2
answers
98
views
Using operators, how to set a variable equal to one of two other variables depending on which one has a value, in Ruby? [closed]
When there are only two states for instance variable "a", either it has a value or not, and there is only one possible state for instance variable "b", it has a value. I can set &...
1
vote
1
answer
193
views
what is [] operator in Ruby
I don't get it that [] is an operator in ruby. I was wondering that if [] is an operator then what are these parenthesis {} & (). Are these also operators?
What I know is that these symbols are ...
0
votes
2
answers
72
views
What is << stand for in ruby with integer
What is use of << I understand in array it is used for push but here I am not clear what is purpose of this in following code. Where it is being used integer.
def array_pack(a)
a.reverse....
- 2,393
1
vote
4
answers
99
views
Is the order of the equality operator important in Ruby?
I have used the bcrypt library in my Ruby program. I noticed that the order of the equality operator seems to be important. Depending on which variable is left or right of the '==' I get a different ...
- 608
0
votes
2
answers
156
views
Can operator precedence be changed in Ruby?
In Ruby, the operator precedence is (implicitly) defined, and documented in a couple of places, for example at Ruby operator precedence table.
Some languages allow setting or changing the operator ...
- 6,784
0
votes
2
answers
60
views
What does shorthand operator like (+=) in ruby really does?
While I can understand that x += 1 is equivalent to x = x + 1, I'm interested what it does in the background.
I've tried in irb with x += 1 without first assigning value to x and surely I get an error,...
- 161
2
votes
2
answers
1k
views
Logic OR / AND term evaluation order in Ruby
In Ruby, for the binary logic operators AND and OR, what's the order of evaluation of the terms, i.e., in an instruction like
if bool1 || bool2
which boolean value is checked first? Is it left to ...
- 204
-2
votes
1
answer
189
views
What is the meaning of operator ==~ in Ruby? [duplicate]
I am modifying an existing ruby code. It has the following lines of code. Can somebody tell me what is going on.
if string ==~ /^ABC/
do-something
elsif string == "some string"
do-...
- 174
-1
votes
3
answers
89
views
how can i rename a operator method with words, respecting sintax in ruby?
I'm trying to add an alias to a class method that uses an operator in ruby. My problem is that i would like to keep the new alias with the sintax of the operator
def &(estrategia)
does something
...
- 33
9
votes
2
answers
3k
views
Rails—what does &= do?
To help future searches, it could also be described as "and equals" or "ampersand equals".
I found this line in the Rails source code:
attribute_names &= self.class.column_names
What is the ...
- 12.4k
1
vote
4
answers
886
views
MULTIPLYING an array ELEMENT in while loop ruby
I have an array of integers, and I am attempting to multiply every second element by 2 moving backwards in the array. However, it does not seem to accept the * operator on the array item, results in ...
- 127
2
votes
1
answer
192
views
Is there an alternate syntax in Ruby for backticks?
In Ruby you can do a + b, which is equivalent to a.+(b).
You can also override the +() method with def +(other); end.
Is there an alternate syntax for backticks? I know that this works:
class Foo
...
- 3,056
0
votes
4
answers
64
views
Ruby: why this WHEN-statement doesn't work with two conditions?
I have a case in my Ruby code that basically tries to match string in a couple of ways and do different things to it accordingly, kind of like that:
case inst
when Rx_inst1
(some function)
when ...
- 655