a = []
=> []a ||=[]
=> []a =[2,5,4]
=> [2, 5, 4]a ||=[2,5,4]
=> [2, 5, 4]a |=[2,5,4]
=> [2, 5, 4]
In the above code I am not able to understand the difference between
“||=” and “|=”.
Any help on this regard?
Huum, Interesting from the below code I got the taste :
a = [2,3,4]
=> [2, 3, 4]a||=[2,1,4,6]
b ||= [2,33]
=> [2, 33]b ||= [21,33]
=> [2, 33]
From the above code it is clear that “||=” operators set the variable
conditionally. Condition is like that if the variable is set to “false
or nil” then set it or return it’s already set value.
=> [2, 3, 4]
a |= [2,1,4,6]
=> [2, 3, 4, 1, 6]a = [1,2,3]
=> [1, 2, 3]a |= [4,5]
=> [1, 2, 3, 4, 5]a |= [4,5,6]
=> [1, 2, 3, 4, 5, 6]
From the above code I can say that “|=” operator performing kind of
concatenation and if delicates then remove it away.
If any wrong logic I said here, forgive me and correct me please.
On the same road I tried to the “&&=” as below :
a = []
=> []a &&= [4,1]
=> [4, 1]a &&= [42,111]
=> [42, 111]
Couldn’t reach to any summary. How does it work?
ary | other_ary -> new_ary
Set Union—Returns a new array by joining this array with
other_ary, removing duplicates.
[ “a”, “b”, “c” ] | [ “c”, “d”, “a” ]
#=> [ “a”, “b”, “c”, “d” ]
Justin C. wrote in post #1098508:
On 02/22/2013 01:08 PM, Xavier R. wrote:
Couldn’t reach to any summary. How does it work?
Ruby Programming/Syntax/Operators - Wikibooks, open books for an open world
from your reference -
x &&= x.next_node #=> nil : x will be set to x.next_node, but only if x
is NOT nil or false.
then how the below works?
a = []
=> []
a &&= [2,3]
=> [2, 3]
On 02/22/2013 01:08 PM, Xavier R. wrote:
Couldn’t reach to any summary. How does it work?
https://en.wikibooks.org/wiki/Ruby_Programming/Syntax/Operators#1._Assignment
On 02/22/2013 01:32 PM, Xavier R. wrote:
from your reference -
Is a nil or false?
[] is not nil or false
if []
p “like true”
else
p “like false”
end
guess what this lines will output?
Justin C. wrote in post #1098511:
On 02/22/2013 01:32 PM, Xavier R. wrote:
from your reference -
Is
anil or false?
@justin not understood your point? yes the a is empty as we can see
below:
a = []
=> []a.empty?
=> true
On Fri, Feb 22, 2013 at 11:51 PM, Xavier R. [email protected]
wrote:
guess what this lines will output?
got the point. Could you give me a valid example of “&&=” ?
I think I have something even better: advice how to find out yourself.
Fire up IRB and then start experimenting. It’s best to start from
simple expressions, so first for different combinations of a and b do
a && b
Look at the result. Then do
a &&= b
a ||= b
Reason about what you see. If unsure, do more tests.
Kind regards
robert
Hans M. wrote in post #1098517:
[] is not nil or false
if []
p “like true”
else
p “like false”
endguess what this lines will output?
got the point. Could you give me a valid example of “&&=” ?
Justin C. wrote in post #1098508:
On 02/22/2013 01:08 PM, Xavier R. wrote:
Couldn’t reach to any summary. How does it work?
Thanks for the below link, all has been explained well.