Array Initialization In C

There are two main ways to initialize an array:

1. At the time of declaration (static initialization).
2. Element-by-element assignment after declaration (dynamic initialization).

Array declaration and Initialization example

int intArray[5] = {1, 2, 3, 4, 5};

char charArray[5] = {'a', 'b', 'c', 'd', 'e'};

float floatArray[5] = {1.1, 2.2, 3.3, 4.4, 5.5};

double doubleArray[5] = {1.111, 2.222, 3.333, 4.444, 5.555};

long longArray[5] 
= {1000000000, 2000000000, 3000000000, 4000000000, 5000000000};

short shortArray[5] = {1, 2, 3, 4, 5};

unsigned int unsignedIntArray[5] = {1, 2, 3, 4, 5};

unsigned long unsignedLongArray[5] 
= {1000000000, 2000000000, 3000000000, 4000000000, 5000000000};

unsigned short unsignedShortArray[5] = {1, 2, 3, 4, 5};

int boolArray[2] = {1, 0}; // true, false

Different Type of Declaration and initialization of array in c

In C programming, you can declare and initialize an array in various ways. Here are some common methods:

1. Static Initialization: Declare and initialize the array with predefined values at the time of declaration.
   

       int arr1[5] = {1, 2, 3, 4, 5};
       

2. Dynamic Initialization: If you're initializing the array dynamically, you can use a loop or other logic to assign values.

       int arr2[5];
       for (int i = 0; i < 5; i++) {
       arr2[i] = i + 1;
       }
       

3. Partial Initialization: You can partially initialize an array, and the remaining elements will be automatically initialized to 0.

       int arr3[5] = {1, 2}; // arr3[0] = 1, arr3[1] = 2, arr3[2] = 0, arr3[3] = 0, arr3[4] = 0
       

4. Designated Initializers (C99 and later): You can specify which elements of the array you want to initialize.

       int arr4[5] = {[0] = 1, [2] = 3}; // arr4[0] = 1, arr4[1] = 0, arr4[2] = 3, arr4[3] = 0, arr4[4] = 0
       

5. String Initialization: Arrays can be initialized with strings. Strings in C are arrays of characters.

       char str[] = "Hello"; // str[0] = 'H', str[1] = 'e', ..., str[4] = 'o', str[5] = '\0'