The format of a variable declaration is type identifier; or type identifier1, identifiers, ... ;.
Here, type is one of the data types that we encountered earlier and identifier is the name of the variable we are declaring. In the first example, a single variable is declared. In the second form, multiple variables are declared, each having the same type, separated by commas. Note that each one is a C statement because it concludes with;. Consider the following variable declarations:
#include <stdbool.h> /* So we can use: bool, true, false */
int aNumber;
long aBigNumber;
long long aReallyBigNumber;
float inches;
float feed;
float yards;
double length, width, height;
bool isItRaining;
In each of these declarations, we use spacing to make the type and name of each variable easier to read. Unfortunately, these declarations are not necessarily the best we could use. The values of the variables...