1.25. C # Array

1.25.1. Declare array #

To declare an array in C #, you can use the following syntax:

datatype[] arrayName; 

Among them

• datatype use to specify the type of element stored in the array.

• [ ] specifies the rank (dimension) of the array. Rank specifies the sizeof the array.

• arrayName specifies the name of the array.

For example:

double[] balance; 

1.25.2. Initialize array #

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

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

For example:

double[] balance = new double[10]; 

1.25.3. Assign values to an array #

You can assign values to a single array element by using index numbers, suchas:

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

You can assign values to an array while declaring it, such as:

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

You can also create and initialize an array, such as:

int [] marks = new int[5] { 99, 98, 92, 97, 95}; 

In the above cases, you can also omit the size of the array, such as:

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

You can also assign an array variable to another target array variable. In this case, the destination and source point to the same memory location:

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

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

1.25.4. Access array elements #

The element is accessed through the indexed array name. This is achieved by placing the index of the element in square brackets after the array name. For example:

double salary = balance[9]; 

Here is an example that uses the three concepts mentioned above, namely, declare, assign, and access arrays:

using System; namespace ArrayApplication { class MyArray { static void Main(string[] args) { int [] n = new int[10]; /* n is an array with 10 integers */ int i,j; /* Initialize elements in array n */ for ( i = 0; i < 10; i++ ) { n[ i ] = i + 100; } /* Output the value of each array element */ for (j = 0; j < 10; j++ ) { Console.WriteLine("Element[{0}] = {1}", j, n[j]); } Console.ReadKey(); } } } 

Element[0] = 100 Element[1] = 101 Element[2] = 102 Element[3] = 103 Element[4] = 104 Element[5] = 105 Element[6] = 106 Element[7] = 107 Element[8] = 108 Element[9] = 109 

1.25.5. Use foreach Cycle #

In the previous example, we used a for loop to access each array element. You can also use a foreach statement to traverse the array.

using System; namespace ArrayApplication { class MyArray { static void Main(string[] args) { int [] n = new int[10]; /* n is an array with 10 integers */ /* initialize elements in array n */ for ( int i = 0; i < 10; i++ ) { n[i] = i + 100; } /* Output the value of each array element */ foreach (int j in n ) { int i = j-100; Console.WriteLine("Element[{0}] = {1}", i, j); } Console.ReadKey(); } } } 

Element[0] = 100 Element[1] = 101 Element[2] = 102 Element[3] = 103 Element[4] = 104 Element[5] = 105 Element[6] = 106 Element[7] = 107 Element[8] = 108 Element[9] = 109 

1.25.6. C # array details #

In C #, arrays are very important and you need to know more details. Here are some important array-related concepts that C # programmers must be awareof: