Increment/Decrement Operators for String, Boolean, Floating-point and Object

Operand	Action	Return Type
String with valid number value	convert to number and do the calculation	number
String with invalid number value	convert string to NaN	number
Boolean false value	convert to 0 and do the calculation	number
Boolean true value	convert to 1 and do the calculation	number
Floating-point value	add or subtract 1	number
Object	call valueOf method and do the calculation. If the result is NaN call toString method	number

 
<!DOCTYPE html>
<html>
<head>
    <title>Operator Example</title>
    <script type="text/javascript">

        var s1 = "2"; 
        var s2 = "A"; 
        var s3 = "2.1"; 
        var s4 = "0xAA"; 
        var b  =  true; 
        var b2 = false; 
        var f  = 1.1; 
        var o  = { 
            valueOf: function() { 
               return 10; 
            } 
        }; 
        
        document.writeln(s1);
        document.writeln(s2);
        document.writeln(s3);
        document.writeln(s4);
        document.writeln(b);
        document.writeln(b2);
        document.writeln(f);
        document.writeln(o);
        
        s1++; 
        s2++; 
        s3++; 
        s4++; 
        b++; 
        b2++; 
        f++; 
        o++;

        document.writeln(s1);
        document.writeln(s2);
        document.writeln(s3);
        document.writeln(s4);
        document.writeln(b);
        document.writeln(b2);
        document.writeln(f);
        document.writeln(o);
        
    </script>

</head>
<body>
  
</body>
</html>

Click to view the demo

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Operators:

JavaScript Operators
Increment/Decrement Operators
Increment/Decrement Operators for String, Boolean, Floating-point and Object
Unary Plus and Minus
Bitwise Not operator
Bitwise AND
Bitwise OR
Bitwise XOR
Left Shift
Signed Right Shift
Unsigned Right Shift
Logical NOT
Logical AND
Logical OR
Multiply
Divide
Modulus
Add
Subtract
Relational Operators
Equal and Not Equal
Identically Equal and Not Identically Equal
Conditional Operator
Assignment Operators
Comma Operator