The Go Programming Language

2.5 Type Declarations

The type of a variable or expression defines the characteristics of the values it may take on, such as their size (number of bits or number of elements, perhaps), how they are represented internally, the intrinsic operations that can be performed on them, and the methods associated with them.

In any program there are variables that share the same representation but signify very different concepts. For instance, an int could be used to represent a loop index, a timestamp, a file descriptor, or a month; a float64 could represent a velocity in meters per second or a temperature in one of several scales; and a string could represent a password or the name of a color.

A type declaration defines a new named type that has ...