Data Types in C

The C programming, data types define the type of data that a variable can hold. C provides a range of data types to accommodate different types of data, from integers and floating-point numbers to characters and user-defined types. Here are some commonly used data types in C:

1. Integers:

• int: Used for integer values.
• short: Used for short integers (typically 16 bits).
• long: Used for long integers (typically 32 bits).
• long long: Used for very long integers (typically 64 bits).
• Example:

int age = 30; long long population = 7000000000LL; 
// Note the LL suffix for long long literals

1. Floating-Point Numbers:

• float: Used for single-precision floating-point numbers.
• double: Used for double-precision floating-point numbers (default for floating-point literals).
• long double: Used for extended-precision floating-point numbers.
• Example:

float pi = 3.14159f;    // Note the f suffix for float literals
double e = 2.71828;     // Double is the default for floating-point literal

1. Characters:

• char: Used for single characters.
• Example:

char grade = 'A';

1. Boolean:

• _Bool (or bool after including <stdbool.h>): Used for Boolean values (true or false).
• Example (with stdbool.h):

#include <stdbool.h>
bool isStudent = true;

1. Enumerations (Enums):

• enum: Used to define a user-defined data type that represents a set of named integer constants.
• Example:

enum Color { 
  RED, GREEN, BLUE 
}; 
enum Color selectedColor = GREEN;

1. Void:

• void: Typically used as a return type for functions that do not return a value.
• Example:

void printMessage() { 
  printf("Hello, world!\n"); 
}

1. Pointers:

• int*: Pointer to an integer.
• float*: Pointer to a float.
• char*: Pointer to a character (often used for strings).
• Example:

c int num = 42; 
int* ptr = # // Pointer to an integer

1. Arrays:

• int[]: Array of integers.
• char[]: Array of characters (strings are represented as character arrays).
• Example:

int numbers[5] = {1, 2, 3, 4, 5}; 
char name[] = "John";

1. User-Defined Types:

• struct: Used to define user-defined composite data types (structures).
• union: Used to define unions, which can hold one value from a set of possible types.
• Example:

struct Person { 
  char name[50]; int age; 
}; 
union Data { 
  int intValue; 
  float floatValue; 
};

These are some of the fundamental data types in C. C also allows for type modifiers, such as signed, unsigned, const, and others, to further refine the behavior of these basic data types. Understanding data types is essential for declaring variables and specifying the type of data they will hold.