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Next: Accessing Array Elements
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An array declaration is very similar to a variable declaration. First a type is given for the elements of the array, then an identifier for the array and, within square brackets, the number of elements in the array. The number of elements must be an integer.
For example data on the average temperature over the year in Britain for each of the last 100 years could be stored in an array declared as follows:
float annual_temp[100];
This declaration will cause the compiler to allocate space for 100
consecutive float variables in memory. The number of elements
in an array must be fixed at compile time. It is best to make the
array size a constant and then, if required, the program can be
changed to handle a different size of array by changing the value of
the constant,
const int NE = 100; float annual_temp[NE];then if more records come to light it is easy to amend the program to cope with more values by changing the value of
NE. This works
because the compiler knows the value of the constant NE at
compile time and can allocate an appropriate amount of space for the
array. It would not work if an ordinary variable was used for the
size in the array declaration since at compile time the compiler would
not know a value for it.