Essentials of Javascript - Cultural View

JavaScript syntax 30
Operators
The '+' operator is overloaded; it is used for string concatenation and arithmetic addition and also to convert strings
to numbers. It also has special meaning when used in a regular expression.
// Concatenate 2 strings
var a = 'This';
var b = ' and that';
alert(a + b); // displays 'This and that'
// Add two numbers
var x = 2;
var y = 6;
alert(x + y); // displays 8
// Adding a string and a number results in concatenation
alert(x + '2'); // displays 22
// Convert a string to a number
var z = '4'; // z is a string (the digit 4)
var x = '2'; // x is a string (the digit 2)
alert(z + x); // displays 42
alert(+z + +x);// displays 6
Arithmetic
JavaScript supports the following binary arithmetic operators:
+ Addition
- Subtraction
* Multiplication
/ Division (returns a floating-point value)
% Modulus (returns the integer remainder)
JavaScript supports the following unary arithmetic operators:
+ Unary conversion of string to number
- Unary negation (reverses the sign)
++ Increment (can be prefix or postfix)
-- Decrement (can be prefix or postfix)
var x = 1;
alert( ++x ); // displays: 2
alert( x++ ); // displays: 2
alert( x ); // displays: 3
alert( x-- ); // displays: 3
alert( x ); // displays: 2
alert( --x ); // displays: 1