mmt-001-solved-assignment-2024-ss-8e24e610-06c9-4b43-84f6-a5bf6ef5ab5c

1. Write the output of the following $\mathrm{C}$$\mathrm{C}$C\mathrm{C}$\mathrm{C}$ codes, with proper justification for each.
   i)
   main()
   {
   int $\mathrm{a}=2,\mathrm{b}=4,\mathrm{c}=5$$\mathrm{a}=2,\mathrm{b}=4,\mathrm{c}=5$a=2,b=4,c=5\mathrm{a}=2, \mathrm{~b}=4, \mathrm{c}=5$\mathrm{a}=2,\mathrm{b}=4,\mathrm{c}=5$;
   $\mathrm{a}=\mathrm{b}+\mathrm{c}$$\mathrm{a}=\mathrm{b}+\mathrm{c}$a=b+c\mathrm{a}=\mathrm{b}+\mathrm{c}$\mathrm{a}=\mathrm{b}+\mathrm{c}$;
   $\mathrm{b}=\mathrm{a}+\mathrm{c}$$\mathrm{b}=\mathrm{a}+\mathrm{c}$b=a+c\mathrm{b}=\mathrm{a}+\mathrm{c}$\mathrm{b}=\mathrm{a}+\mathrm{c}$;
   $\mathrm{c}=\mathrm{a}-\mathrm{b}$$\mathrm{c}=\mathrm{a}-\mathrm{b}$c=a-b\mathrm{c}=\mathrm{a}-\mathrm{b}$\mathrm{c}=\mathrm{a}-\mathrm{b}$;
   printf ("%d,%d,%d", a, b, c);
   }

1. Initialization:
   • a = 2
   • b = 4
   • c = 5
2. First Assignment:
   • a = b + c
   • a = 4 + 5
   • a = 9
3. Second Assignment:
   • b = a + c
   • b = 9 + 5
   • b = 14
4. Third Assignment:
   • c = a - b
   • c = 9 - 14
   • c = -5
5. Output:
   • printf("%d,%d,%d", a, b, c);
   • The output will be: 9,14,-5

• ‘C’ = 67
• ‘P’ = 80
• ‘r’ = 114
• ‘o’ = 111
• ‘g’ = 103
• ‘r’ = 114
• ‘a’ = 97
• ‘m’ = 109

1. Initialization:
   • j = 1
2. For Loop:
   • The loop runs for i = 1, 3, 5, 7, 9.
3. Inside the For Loop:
   • For each iteration of the for loop, j is updated as j = i - j.
   • Then, a while loop runs as long as j <= 2, printing i + j and incrementing j by 1 each time.

• First Iteration (i = 1):
  • j = 1 - 1 = 0
  • While loop: j <= 2, so it prints 1 + 0 = 1, then j becomes 1 and prints 1 + 1 = 2, then j becomes 2 and prints 1 + 2 = 3, then j becomes 3 and the loop stops.
• Second Iteration (i = 3):
  • j = 3 - 2 = 1
  • While loop: j <= 2, so it prints 3 + 1 = 4, then j becomes 2 and prints 3 + 2 = 5, then j becomes 3 and the loop stops.
• Third Iteration (i = 5):
  • j = 5 - 1 = 4
  • While loop: j > 2, so it doesn’t print anything.
• Fourth Iteration (i = 7):
  • j = 7 - 4 = 3
  • While loop: j > 2, so it doesn’t print anything.
• Fifth Iteration (i = 9):
  • j = 9 - 3 = 6
  • While loop: j > 2, so it doesn’t print anything.

int val = 2;
int *p = &val;

int p = 2;

main()
{
    int a = 10, b = 20, c = 30;
    int p = 2;
    a = c / p;
    b = c;
    printf("a = %d, b = %d", a, b);
}

• a is assigned the value of c / p, which is 30 / 2 = 15.
• b is assigned the value of c, which is 30.

a = 15, b = 30

#include <stdio.h>

int fun(int x)
{
    static int a = 0;
    a += x;
    return a;
}

int main()
{
    int p;
    for (p = 1; p <= 5; ++p)
        printf("%d ", fun(p));
    return 0;
}

1. Function fun: This function takes an integer x as an argument and has a static integer variable a. The static variable a retains its value between function calls. In each call, x is added to a, and the updated value of a is returned.
2. Main Function:
   • A for loop runs from p = 1 to p = 5.
   • In each iteration, the function fun is called with the current value of p, and the returned value is printed.

• First Iteration (p = 1): a = 0 + 1 = 1, prints 1.
• Second Iteration (p = 2): a = 1 + 2 = 3, prints 3.
• Third Iteration (p = 3): a = 3 + 3 = 6, prints 6.
• Fourth Iteration (p = 4): a = 6 + 4 = 10, prints 10.
• Fifth Iteration (p = 5): a = 10 + 5 = 15, prints 15.

2. (a) Explain the use of the functions getchar(), putchar(), gets() and puts() functions, with a suitable program.

1. getchar(): This function is used to read a single character from the standard input (usually the keyboard). It doesn’t take any arguments and returns the read character. If there’s an error or end of file is reached, it returns EOF.
2. putchar(): This function is used to write a single character to the standard output (usually the console). It takes a character as an argument and returns the written character. If there’s an error, it returns EOF.
3. gets(): This function is used to read a string from the standard input into a buffer until a newline character is encountered or end of file is reached. It’s considered unsafe because it can lead to buffer overflow, so it’s better to use fgets() instead.
4. puts(): This function is used to write a string to the standard output followed by a newline character. It takes a string as an argument and returns a non-negative number if successful, or EOF if there’s an error.

#include <stdio.h>

int main() {
    char c;
    char str[100];

    printf("Enter a character: ");
    c = getchar(); // Read a character

    printf("You entered: ");
    putchar(c); // Write the character
    printf("\n");

    printf("Enter a string: ");
    gets(str); // Read a string (unsafe, consider using fgets instead)

    printf("You entered: ");
    puts(str); // Write the string with a newline

    return 0;
}

• getchar() is used to read a single character from the user.
• putchar() is used to display the entered character.
• gets() is used to read a string from the user (though it’s unsafe and not recommended).
• puts() is used to display the entered string with a newline at the end.

1. * (unary): Unary operators have the highest precedence among the listed operators. Associativity: Right to left.
2. ++ (unary): Unary increment operator has the same precedence as the unary * operator. Associativity: Right to left.
3. * (binary): Binary multiplication operator. Associativity: Left to right.
4. %: Remainder operator has the same precedence as the binary * operator. Associativity: Left to right.
5. +: Binary addition operator. Associativity: Left to right.
6. -: Binary subtraction operator has the same precedence as the binary + operator. Associativity: Left to right.
7. !=: Inequality operator. Associativity: Left to right.
8. +=: Addition assignment operator has the lowest precedence among the listed operators. Associativity: Right to left.

• * (unary), ++ (unary) [Right to left]
• * (binary), % [Left to right]
• +, - (binary) [Left to right]
• != [Left to right]
• += [Right to left]

#include <stdio.h>
#include <ctype.h>

int main() {
    char text[] = "Hello, World! 12345 \t\n";
    int letters = 0, digits = 0, whitespace = 0, others = 0;

    for (int i = 0; text[i] != '\0'; i++) {
        if (isalpha(text[i])) {
            letters++;
        } else if (isdigit(text[i])) {
            digits++;
        } else if (isspace(text[i])) {
            whitespace++;
        } else {
            others++;
        }
    }

    printf("Letters: %d\n", letters);
    printf("Digits: %d\n", digits);
    printf("Whitespace characters: %d\n", whitespace);
    printf("Other characters: %d\n", others);

    return 0;
}

• isalpha() checks if a character is an alphabetic letter.
• isdigit() checks if a character is a digit.
• isspace() checks if a character is a whitespace character (space, tab, newline, etc.).
• The loop continues until it encounters the null terminator '\0' at the end of the string.