4.3. Operators

JavaScript has a number of operators that you might or might not be familiar with. These include the ever-present == (equals) and != (not equals), to which you have undoubtedly been exposed; there are a number of others. Although some of these operators are familiar, some others might not be as familiar, so Table 4-4 briefly touches upon these.

Table 4-4. JavaScript Operators

Operator	Type	Description
a + b	Arithmetic	Addition
a - b	Arithmetic	Subtraction
a* b	Arithmetic	Multiplication
a / b	Arithmetic	Division
a % b	Arithmetic	Modulus, the remainder to division
++a	Arithmetic	Increment by one
--a	Arithmetic	Decrement by one
a = b	Assignment	Set equal to
a += b	Assignment	Increment by the value on the right
a -= b	Assignment	Decrement by the value on the right
a *= b	Assignment	Multiply by the value on the right
a /= b	Assignment	Divide by the value on the left
a %= b	Assignment	Modulus by the value on the right
a == b	Comparison	Equal to, value
a === b	Comparison	Equal to, value and type
a != b	Comparison	Not equal to
a > b	Comparison	Greater than
a < b	Comparison	Less than
a >= b	Comparison	Greater than/equal to
a <= b	Comparison	Less than/equal to
a && b	Logical	And
a || b	Logical	Or
!a	Logical	Not
a + b	String	String concatenation
a=(condition)?b:c	Comparison	Comparison operator
typeof(a)	Special	Returns a string consisting of the operand type
void a	Special	Suppresses the return of a variable

I'll bet you didn't know that typeof was an operator.