C Programming - C Data Types

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C Programming - C Data Types

C Data Types

In C programming, data types specify the type of data a variable can hold. They determine the size, range, and operations that can be performed on the variable.

Categories of Data Types

1. Basic Data Types:
• int, float, char, double
2. Derived Data Types:
• Arrays, Pointers, Structures, Unions
3. Enumeration Data Type:
• enum
4. Void Data Type:
• void

1. Basic Data Types

Examples

int age = 25;
float salary = 50000.50;
char grade = 'A';
double distance = 1234567.89;

2. Derived Data Types
3. a) Arrays

• Store multiple elements of the same type.

Example:

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

1. b) Pointers

• Store the address of a variable.

Example:

int x = 10;
int *ptr = &x;  // Pointer to x

1. c) Structures

• Group different types of data.

Example:

struct Student {
    int id;
    char name[50];
    float marks;
};

1. d) Unions

• Share memory among variables.

Example:

union Data {
    int i;
    float f;
};

3. Enumeration Data Type

• Used to define named integer constants.

Example:

enum Day { Sunday, Monday, Tuesday };
enum Day today = Monday;

4. Void Data Type

• Represents "no value."
• Used in functions that do not return a value.

Example:

void displayMessage() {
    printf("Hello, World!\n");
}

Modifiers in C

Data types can be modified to change their size and range using modifiers like:

• Signed
• Unsigned
• Short
• Long

Example

Example Code: Data Types in Action

#include <stdio.h>
 
int main() {
    int age = 25;
    float height = 5.9;
    char grade = 'A';
    double pi = 3.14159265358979;
    unsigned int score = 4294967295;

    printf("Age: %d\n", age);
    printf("Height: %.1f\n", height);
    printf("Grade: %c\n", grade);
    printf("Value of Pi: %.15lf\n", pi);
    printf("Score: %u\n", score);

    return 0;
}

Key Points

1. Choose Data Types Wisely:
• Use int for general numbers, float/double for decimals, and char for characters.
2. Memory Matters:
• Smaller data types save memory but have smaller ranges.
3. Type Conversion:
• Implicit (automatic) or explicit (casting) conversions can occur between data types.