Ruby  Operators
Operators are used to perform operation on a single operand or two operands. Operators in Ruby can be categorized as follows:
 Arithmetic operators
 Assignment operators
 Comparison operators
 Logical operators
 Bitwise operators
 Miscellaneous operators
Ruby Arithmetic operators
Arithmetic operators are used to perform arithmetic operations on two operands.
Operator  Name  Description 

+  Addition  Add two values 
  Subtraction  Subtract one value from another 
*  Multiplication  Multiply two values 
/  Division  Divide one value by another 
%  Modulo  Returns remainder of division operation 
**  Exponent / Power  Returns first operand raised to the power of second operand 
Example
Ruby Assignment operators
Assignment operators are used to assign values of right hand side expression to left hand side operand.
Operator  Expression  Equivalent to  Description 

=  a = 5  a = 5  Example 
+=  a += b  a = a + b  
=  a = b  a = a  b  
*=  a *= b  a = a * b  
/=  a /= b  a = a / b  
%=  a %= b  a = a % b  
**=  a **= b  a = a ** b  
&=  a &= b  a = a & b  More Info 
=  a = b  a = a  b  More Info 
^=  a ^= b  a = a ^ b  More Info 
>>=  a >>= b  a = a >> b  More Info 
<<=  a <<= b  a = a << b  More Info 
Ruby Comparison operators
Comparison operators are used to compare values of two operands. It returns true when values matches and returns false when values does not match.
Operator  Description 

==  Equal: Checks the values of two operands and returns true if they are same. 
!=  Not equal: Checks the values of two operands and returns true if they are not same. 
===  Case equality: A === B, Checks if B is a member of the set of A. 
>  Greater than: Checks the values of two operands and returns true if the value of first operand is greater than the value of second operand. 
<  Less than: Checks the values of two operands and returns true if the value of first operand is less than the value of second operand. 
>=  Greater than or equal to: Checks the values of two operands and returns true if the value of first operand is greater than or equal to the value of second operand. 
<=  Less than or equal to: Checks the values of two operands and returns true if the value of first operand is less than or equal to the value of second operand. 
<=>  Combined Comparison Operator: Checks the values of two operands and returns values based on the values of two operands:

.eql?  Equal: Checks the values and datatypes of two operands and returns true if they are same. 
Example
Ruby Logical operators
Logical operators are used to combine two or more conditions.
Operator  Name  Description 

and  Logical AND  Returns true when all conditions are true 
&&  
or  Logical OR  Returns true when any of the conditions is true 
  
not  Logical NOT  Returns true when given conditions is not true 
! 
More Info
Ruby Bitwise operators
Bitwise operators are used to perform bitwise operations on two operands.
Operator  Name  Description  More Info 

&  AND  Returns 1 if both bits at the same position in both operands are 1, else returns 0.  More Info 
  OR  Returns 1 if one of two bits at the same position in both operands is 1, else returns 0.  More Info 
^  XOR  Returns 1 if only one of two bits at the same position in both operands is 1, else returns 0.  More Info 
~  NOT  Reverse all the bits.  More Info 
>>  Right shift  The left operand is moved right by the number of bits present in the right operand.  More Info 
<<  Left shift  The left operand value is moved left by the number of bits present in the right operand.  More Info 
Ruby Miscellaneous operators
The table below describes other operators supported by Ruby:
Operator  Description 

ternary operator (?:)  Returns one of the two values based on value of boolean expression. 
range operator (..)  Creates a range from start point to end point inclusive. 
range operator (...)  Creates a range from start point to end point exclusive. 
Ruby Operators Precedence
Operator precedence (order of operations) is a collection of rules that reflect conventions about which procedures to perform first in order to evaluate a given expression.
For example, multiplication has higher precedence than addition. Thus, the expression 1 + 2 × 3 is interpreted to have the value 1 + (2 × 3) = 7, and not (1 + 2) × 3 = 9. When exponent is used in the expression, it has precedence over both addition and multiplication. Thus 3 + 5^{2} = 28 and 3 × 5^{2} = 75.
The following table lists the precedence and associativity of Ruby operators. Operators are listed top to bottom, in descending precedence. Operators with higher precedence are evaluated before operators with relatively lower precedence.
Precedence  Operator  Description 

21  !  Logical NOT 
~  Bitwise NOT  
+a  Unary plus  
20  **  Exponential operator 
19  a  Unary minus 
18  * / %  Multiplication, Division, Remainder 
17  +   Addition, Subtraction 
16  << >>  Bitwise left shift and right shift 
15  &  Bitwise AND 
14    Bitwise OR 
^  Bitwise XOR  
13  < <= > >=  Less than, Less than or equal, Greater than, and Greater than or equal 
12  == !=  Equality and Inequality 
=== <=>  Case equality, Combined Comparison Operator  
=~ !~  Pattern matching operators  
11  &&  Logical AND 
10    Logical OR 
9  ..  Range creation operators 
...  
8  a?b:c  ternary (conditional) operator 
7  modifierrescue  Exceptionhandling modifier 
6  =  Direct assignment 
+= = *= /= %= **=  Compound assignment by sum, difference, product, quotient, remainder and exponential  
<<= >>=  Compound assignment by Bitwise left shift and right shift  
&= ^= =  Compound assignment by Bitwise AND, XOR and OR  
5  defined?  Test variable definition and type 
4  not  Logical NOT 
3  and  Logical AND 
or  Logical OR  
2  modifierif modifierunless modifierwhile modifieruntil  Conditional and loop modifiers 
1  { }  blocks 