1. COMP102 Lab 081 COMP 102 Programming Fundamentals I Presented by : Timture Choi

2. COMP102 Lab 082 Arrays An array is a collection of data elements That are of the same type E.g. Collection of integers  Integer array Collection of characters  Character array Each data in the collection is called An element

3. COMP102 Lab 083 Array Declaration Syntax: [ ]; E.g. int array[10]; Array elements Are values of the type  E.g.  All element stored in “ int array[10] ” are integer

4. COMP102 Lab 084 Array Declaration Size of the array Represent the number of elements in the array Indicated by E.g.  “ int array[10] ” Can use to store 10 integers must be  An int constant  A constant expression Note An array can have multiple dimensions E.g.  int array[10][20];

5. COMP102 Lab 085 Array Declaration E.g. // array of 10 integer // which is uninitialized int array[10]; -- array -- 4 5 6 3 0 2 8 9 7 1

6. COMP102 Lab 086 Subscripting To access an individual element Must apply a subscript to the corresponding array A subscript Use bracketed expression E.g.  array[x] The expression in the brackets Known as the index E.g.  x stated in array[x]

7. COMP102 Lab 087 Subscripting Note First element of array  Has index 0  array[0] Second element of array  Has index 1, and so on  array[1], array[2], array[3], … Last element  Has an index [array_size – 1] array[array_size – 1]  E.g. If an array is declared as array[10]  Last element is array[9]

8. COMP102 Lab 088 Subscripting E.g. // array of 10 uninitialized ints int array[10]; array[3] = 1; int x = array[3]; -- 1 array -- 4 5 6 3 0 2 8 9 7 1

9. COMP102 Lab 089 Subscripting Use for loop to access/process all the elements of an array E.g. for (i=0; i<array_size; i++) { // assign value to an element of array array[i] = x; // assign value of an element to a variable x = array[i]; … }

10. COMP102 Lab 0810 Array Initialization Declaration only reserves memory for the elements in the array No values will be stored To initialize an array Assign value to each of the element E.g. int array[10] = {9, 8, 7, 6, 5, 4, 3, 2, 1, 0}; 876 9 array 432510 4 5 6 3 0 2 8 9 7 1

11. COMP102 Lab 0811 SUMMARY By the end of this lab, you should be able to: Declare and manipulate both  1-D arrays