Operators and Expressions

This section provides descriptions on operators and expressions, including arithmetic, comparison, logical, bitwise, and assignment operators.

What are expressions? Expressions are sequences of literals, variables, and operators that can be evaluated to values.

Operators are the most important parts of expressions. JavaScripts many basic operators divided into several groups:

1. Arithmetic Operator - Taking numeric values and returning a single numeric value. Arithmetic operators include addition (+), subtraction (-), multiplication (*), and division (/), modulus (%), increment (++), decrement (--), and unary negation (-).

2. Comparison Operator - Taking values of any types and returning a single boolean value. Comparison operators include equal (==), not equal (!=), strict equal (===), strict not equal (!==), greater than (>), greater than or equal (>=), less than (<), and less than or equal (<=).

3. Logical Operator - Taking boolean values and returning a single boolean value. Logical operators include logical AND (&&), logical OR (||), and logical NOT (!).

4. Bitwise Operator - Taking bit strings of 32 bits and returning a single numeric value. Bitwise operators include bitwise AND (&), bitwise OR (|), bitwise XOR (^), bitwise NOT (~), left shift (<<), sign-propagating right shift (>>), and zero-fill right shift (>>>).

5. Assignment Operator - Taking a value of any type and returning a single value. An assignment operator assigns a value to its left operand based on the value of its right operand. Assignment operators include simple assignment (=), assignments combined with arithmetic operators (+=, -=, *=, /=, %=), and assignments combined with bitwise operators (&=, ^=, |=, <<=, >>=, >>>=).

A tutorial example will be given in the next section showing examples of different operators and expressions.

Table of Contents

 About This Book

 Introduction to JavaScript

 ECMAScript Language Specification and JavaScript Dialects

Data Types, Variables and Expressions

 Primitive Data Types - Numbers, Strings, and Booleans

 Numeric Value Literals

 String Literials

 Declaring Variables - "var" Statements

Operators and Expressions

 Operators and Expressions - Examples

 Flow Control Statements

 Creating, Accessing, and Manipulating Arrays

 Defining and Calling Functions

 Web Browser Supporting JavaScript

 Server-Side and Client-Side Web Scripting

 Introduction to Objects

 Defining Your Own Object Types

 Inheritance of Properties and Methods through the Prototype Object Chain

 'jrunscript' - JavaScript Shell Command from JDK

 Using Functions as "Function" Objects

 Introduction to Built-in Object Types

 W3C's Document Object Model (DOM) Specifications


 PDF Printing Version