Chapter 2. Types, Values, and Variables
Computer programs work by manipulating values, such as the number 3.14 or the text “Hello World.” The kinds of values that can be represented and manipulated in a programming language are known as types. When a program needs to retain a value for future use, it assigns the value to (or “stores” the value in) a variable. A variable defines a symbolic name for a value and allows the value to be referred to by name.
type to a variable, and you can later assign a value of a different type to
the same variable. Variables are declared with the
uses lexical scoping. Variables declared