Rules for using arrays:

For the examples, assume the declaration:

int myvalues[15];

Rules:

1 - subscripts always start at 0

valid elements then are from myvalues[0] to myvalues[14]

2 - you cannot declare an array with a variable as the number of elements

int number;

int yourvalues[number]; // this is illegal

3 - the [ ] operator transforms the array into an element of the array

myvalues is an array, myvalues[3] is an int

4 - never leave the [ ] empty, except in a function header

myvalues[ ]=0; // this is illegal

float dothis(int values[])  // this is legal

int values []; // this is illegal

5 - omission of the operator [ ] means you are referring to the whole array, not an element

6 - it is illegal to use the whole array in arithmetic operations

myvalues=0; // illegal

myvalues=yourvalues; // illegal

x=myvalues*3; // illegal

7 - When passing arrays to functions, make sure the function expects an array and not an element and vice versa

void dothis(int value[],int n)  // array and integer

void dothat(int value) // expects an integer

...

dothis(myvalues,5); // is OK for the above

dothis(myvalues[3], 5); // is not OK

dothat(myvalues[4]); // is OK

dothat(myvalues); // is not OK

8 - arrays are always passed by reference and can be modified in functions