Explain the structure of C program. Explain type conversion in C. Write a C program to find prime numbers between a range(using function). Explain any 5 string handling functions available in C. Write a C program to print the address of a variable along with its value.

1. Structure of a C Program: A typical C program consists of the following parts:

   • Preprocessor Commands: These are directives for the C preprocessor. They start with a '#' symbol, e.g., #include, #define.
   • Function: A collection of statements that perform a specific task. The 'main()' function is the entry point of a C program.
   • Variables: These are names given to memory locations to store values of a specific type.
   • Statements & Expressions: These can create, manipulate, and control variables and functions.
   • Comments: These are used to provide information about the program to the reader. They are ignored by the compiler.

2. Type Conversion in C: Type conversion in C is a way to convert one data type into another. It can be done in two ways:

   • Implicit Type Conversion: This is done by the compiler automatically.
   • Explicit Type Conversion: This is done by the programmer manually, also known as type casting.

3. C Program to Find Prime Numbers Between a Range:

#include <stdio.h>

int check_prime(int num) {
    int i;
    for(i = 2; i <= num/2; i++) {
        if(num % i == 0)
            return 0;
    }
    return 1;
}

int main() {
    int start, end, i;
    printf("Enter the range: ");
    scanf("%d %d", &start, &end);
    printf("Prime numbers between %d and %d are: ", start, end);
    for(i = start; i <= end; i++) {
        if(check_prime(i))
            printf("%d ", i);
    }
    return 0;
}

4. Five String Handling Functions in C:

   • strcpy(s1, s2): Copies string s2 into string s1.
   • strcat(s1, s2): Concatenates string s2 onto the end of string s1.
   • strlen(s1): Returns the length of string s1.
   • strcmp(s1, s2): Returns 0 if s1 and s2 are the same; less than 0 if s1<s2; greater than 0 if s1>s2.
   • strrev(s1): Reverses the string s1.

5. C Program to Print the Address of a Variable Along with Its Value:

#include <stdio.h>

int main() {
    int var = 5;
    printf("Value: %d\n", var);
    printf("Address: %p", &var);
    return 0;
}

This program will print the value of the variable 'var' and its memory address.