The objects of the Symbol class represent the names present inside the Ruby interpreter. They are usually generated by using :name literal syntax or by using to_sym methods. The similar Symbol objects are created for a given name string for the duration of a program’s execution, regardless of the content and meaning of the name.
Example:
module Geeks1
class Max
end
$a1 = :Max
end
module Geeks2
Max = 1
$a2 = :Max
end
def Max()
end
$a3 = :Max
puts $a1 .object_id
puts $a2 .object_id
puts $a3 .object_id
|
Output:
1675428
1675428
1675428
Explanation: If Max is a constant in context1, a method in context2, or class in the context3, then this :Max will be the same object in all given contexts.
Class Method
all_symbols : This method returns an array of symbols that currently present in the Ruby’s symbol table.
Symbol.all_symbols
Example:
puts Symbol .all_symbols.size
puts Symbol .all_symbols[ 1 , 20 ]
|
Output:
3250
"
#
$
%
&
'
(
)
*
+
,
-
.
/
:
;
<
=
>
?
Instance Methods
- id2name : This method returns a string that is representation of sym.
sym.id2name
Example:
p :Geeks.id2name
p : "Welcome to GeeksforGeeks Portal" .id2name
|
Output:
"Geeks"
"Welcome to GeeksforGeeks Portal"
- inspect : This method return the representation of sym in the form of symbol literal.
sym.inspect
Example:
p :geeks .inspect
p : "welcome to geeksforgeeks portal" .inspect
|
Output:
":geeks"
":\"welcome to geeksforgeeks portal\""
- to_s : This method is similar to Symbol#id2name. This method returns the name or a string that corresponding to sym.
sym.to_s
Example:
p :geeks .to_s
p : "welcome to geeksforgeeks portal" .to_s
|
Output:
"geeks"
"welcome to geeksforgeeks portal"
- <=> :It compares sym to other_sym after calling to_s. It returns -1 if sym is less than other_sym, it returns 0 if sym is equal to other_sym, or it returns +1 if sym is greater than other_sym.
sym <=> other_sym
Example:
a= :geeks
b = : "welcome to geeksforgeeks portal"
puts a<=>b
c= :geeks
puts a<=>c
puts b<=>a
|
Output:
-1
0
1
- == : It returns true if the sym is equal to obj, otherwise it return false.
sym== obj
Example:
a= :geeks
b = : "welcome to geeksforgeeks portal"
puts a==b
c= :geeks
puts a==c
|
Output:
false
true
- [] : This method returns the value of sym.to_s[].
sym[idx] --> char
sym[b, n] --> string
- capitalize : This method is similar to Symbol#to_s.
sym.capitalize
- casecmp : This method is case-insensitive version of symbol <=$gt;. It will return -1, 0, 1, or nil. It is worked on A-Z/a-z, not on all Unicode. In this method nil is returned when the two symbols have incompatible encodings or if other_sym is not a symbol.
sym.casecmp(other)
Example:
puts :GeeKs.casecmp( :geeks )
puts :GeeKsGfg.casecmp( :geeksG )
puts :GeeKsGfg.casecmp( :geeksGfgz )
puts :GeeKsGfg.casecmp( 3 )
|
Output:
0
1
-1
nil
- downcase : This method converts upper-case letters in lower-case.
sym.downcase
Example:
puts : "WELCOME TO GEEKSFORGEEKS" .downcase
|
Output:
:"welcome to geeksforgeeks"
- length : This method returns the length of the given sym.
sym.length
Example:
Output:
8
- slice : This method is similar to Symbol#to_s. This method provides you character on the given index from the sym .
sym.slice(index)
sym.slice(b, n)
Example:
p :GeeKsGfg.slice( 3 )
p :GeeKsGfg.slice( 6 )
|
Output:
"K"
"f"
- swapcase : This method interchange the case of the characters that present in sym. In other words, it converts lower-case into upper-case and upper-case into lower-case.
sym.swapcase
Example:
p "WELcome TO geeksFORGEEKS" .swapcase
|
Output:
"welCOME to GEEKSforgeeks"
- upcase : This method converts lower-case characters into upper-case.
sym.upcase
Example:
p "welcome to geeksforgeeks" .upcase
|
Output:
"WELCOME TO GEEKSFORGEEKS"
- to_proc : This method return a Proc object which answer to the given method by sym.
sym.to_proc
Example:
Output:
["1", "2", "3", "4", "5"]
- to_sym This method returns a symbol that corresponding to an object. Here sym has been already a symbol, so in this case it returns it.
sym.to_sym
Reference: https://ruby-doc.org/core-2.5.0/Symbol.html#method-i-5B-5D
Last Updated :
11 Oct, 2019
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