Chapter 5. Introduction to Variables and Parameters

Table of Contents
5.1. Variable Substitution
5.2. Variable Assignment
5.3. Bash Variables Are Untyped
5.4. Special Variable Types

Variables are at the heart of every programming and scripting language. They appear in arithmetic operations and manipulation of quantities, string parsing, and are indispensable for working in the abstract with symbols - tokens that represent something else. A variable is nothing more than a location or set of locations in computer memory that holds an item of data.