structure Constant in Objective-C

In Objective-C, a constant is a variable whose value cannot be modified once it has been assigned. Constants are declared using the const keyword and can be of any data type.

Here is an example of declaring a constant integer:

const int MAX_COUNT = 100;

In this example, MAX_COUNT is a constant integer with a value of 100. This value cannot be modified throughout the program.

Here is another example of multiple constants declared using #define:

#define PI 3.14159
#define MAX_NAME_LENGTH 50

In this example, PI is a constant double with a value of 3.14159 and MAX_NAME_LENGTH is a constant integer with a value of 50.

Constants can also be used in array declarations. For example:

const int numArray[] = {5, 10, 15, 20};

In this example, numArray is an array of constant integers with values of 5, 10, 15, and 20.

Using constants in Objective-C can help simplify your code by preventing unintentional changes to important values.