%d or %i int printf("Age: %d", age); %f float printf("Pi: %f", pi); %lf double printf("Value: %lf", val); %c char printf("Grade: %c", grade); %s String (char array) printf("Name: %s", name); %p Pointer printf("Address: %p", &var);

Escape Sequences: \n (newline), \t (tab), \\ (backslash), \" (double quote).

Input: scanf()

Syntax: scanf("format string", &variable1, &variable2, ...);
CRITICAL: Use the address-of operator & before variable names to store input. Think of & as telling scanf exactly *where* to put the incoming data, like giving a postal worker the exact address for a package.
Example: int num; scanf("%d", &num);
For strings (char arrays), & is usually not needed as array name itself is a pointer: char name[50]; scanf("%s", name); (Note: scanf("%s", ...) stops at whitespace).

Character I/O: getchar(), putchar(), getch(), getche() (latter two often non-standard).

Practice Problems (Week 2)

Evaluate the following C expression: int x = 5, y = 2; float z = (float)x / y; What is z?
Write a C program that asks the user for two integers, calculates their sum, difference, product, and quotient, and prints all results.

Predict the output:

int a = 10;
printf("%d %d %d\n", a++, ++a, a);

Write a program to read a character from the user and print it.

Week 3: Decision Making and Branching & Switch-Case

Decision Making and Branching (`if` statements)

Definition: Allows your program to execute different blocks of code based on conditions. Like a GPS directing you down different roads based on traffic.

if Statement: Executes a block if a condition is true.

if (condition) {
  // Code to execute if condition is true
}

if-else Statement: Executes one block if true, another if false.

if (condition) {
  // Code for true
} else {
  // Code for false
}

else-if Ladder: Checks multiple conditions sequentially.

if (condition1) {
  // Code for condition1
} else if (condition2) {
  // Code for condition2
} else {
  // Code if none of the above are true
}

Nested if: An if statement inside another if or else block.

`switch-case`