ABC of JavaScript : An Interactive JavaScript Tutorial Operators
Operators
Note : The variable 'a' has the value 3 and 'b' has the value 8. These values will NOT change - in other words, these values will be same for every example.
Arithmetic Operators
Operator
Explanation
Example
Example Result
+
addition
a + b
11
-
subtraction
5 - a
2
*
multiplication
3 * b
24
/
division
6 / a
2
String Operators
In this example a is 'Hello' and b is 'World'.
Operator
Explanation
Example
Example Result
+
concatination
a + b
HelloWorld
Shorthand
Operator
Explanation
Example
Example Result
++
Adds 1 to the value on the left (so if i were equal to 1, i++ would equal 2)
a++
a will be 4
--
Subtracts 1 from the value on the left.
a--
a will be
+=
Adds the values to the left and right of the operator and then stores the value in the left variable.
a += b
a will be 11
-=
Subtracts the values to the left and right of the operator and then stores the value in the left variable.
b -= a
b will be 5
*=
Multiplies the values to the left and right of the operator and then stores the value in the left variable.
a *= b;
a will be 24
Comparison
Operator
Explanation
Example
Example Result
==
equality
if(a == b)
False
!=
inequality
if(a != b)
True
<
less than
if(a < b)
True
>
greater than
if(a > b)
False
<=
less than or equal
if(a <= b)
True
>=
greater than or equal
if(a >= b)
False
Boolean logic
Operator
Explanation
Example
Example Result
&&
AND
if(a>b && b>7)
False
||
OR
if(a>b || b>7)
True
!
NOT
if(!b)
False
Most of these operators are common among other popular languages like C++, Java etc. So if you have any programming experience, you will be well at ease with the operators in JavaScript.
Now lets put those operators to good use by looking at the Control flow structures - where operators will be used most.
