Tutorial C# : ARRAYS / PDF

Tutorial C# : ARRAYS / PDF

An array stores a fixed-size sequential collection of elements of the same type. An array is used to store a collection of data, but it is often more useful to think of an array as a collection of variables of the same type.
Instead of declaring individual variables, such as number0, number1, ..., and number99, you declare one array variable such as numbers and use numbers[0], numbers[1], and ..., numbers[99] to represent individual variables.

 A specific element in an array is accessed by an index.

All arrays consist of contiguous memory locations. The lowest address corresponds to the first element and the highest address to the last element.


Declaring Arrays
To declare an array in C#, you can use the following syntax:
datatype[] arrayName;

where,

• datatype is used to specify the type of elements to be stored in the array.
• [ ] specifies the rank of the array. The rank specifies the size of the array.
• arrayName specifies the name of the array.

For example,

double[] balance;



Initializing an Array

Declaring an array does not initialize the array in the memory. When the array variable is initialized, you can assign values to the array.

Array is a reference type, so you need to use the new keyword to create an instance of the array.

For example,

double[] balance = new double[10];


Assigning Values to an Array
You can assign values to individual array elements, by using the index number, like:

double[] balance = new double[10];
balance[0] = 4500.0;


You can assign values to the array at the time of declaration, like:

double[] balance = { 2340.0, 4523.69, 3421.0};

You can also create and initialize an array, like:

int [] marks = new int[5] { 99, 98, 92, 97, 95};
In the preceding case, you may also omit the size of the array, like:
int [] marks = new int[] { 99, 98, 92, 97, 95};

You can also copy an array variable into another target array variable. In that case, both the target and source would point to the same memory location:

int [] marks = new int[] { 99, 98, 92, 97, 95};
int[] score = marks;

When you create an array, C# compiler implicitly initializes each array element to a default value depending on the array type. For example for an int array all elements would be initialized to 0.

Accessing Array Elements

An element is accessed by indexing the array name. This is done by placing the index of the element within square brackets after the name of the array. For example:........

Tutorial C# : ARRAYS / PDF