Control Statements and Arrays

1. Control Statements

If-Else

The if-else statement allows branching based on conditions, enabling different code paths depending on whether the condition evaluates to true or false.

• Example:

  if (a > b) {
      printf("a is greater");
  } else {
      printf("b is greater");
  }

For Loop

The for loop is used to repeat a block of code a fixed number of times. It consists of three parts: initialization, condition, and increment/decrement.

• Example:

  for (int i = 0; i < 5; i++) {
      printf("%d", i); // Prints numbers from 0 to 4
  }

While Loop

The while loop repeats a block of code as long as a specified condition is true. It checks the condition before each iteration.

• Example:

  int i = 0;
  while (i < 5) {
      printf("%d", i); // Prints numbers from 0 to 4
      i++;
  }

Switch Statement

The switch statement allows multiple conditional checks based on the value of a variable. It simplifies complex conditional structures.

• Example:

  switch(choice) {
      case 1: 
          printf("Option 1"); 
          break;
      case 2: 
          printf("Option 2"); 
          break;
      default: 
          printf("Invalid choice");
  }

Break and Continue

• break: Exits the loop immediately, skipping any remaining iterations.
• continue: Skips the current iteration of the loop and continues with the next iteration.

2. Arrays

Defining an Array

Arrays are used to store multiple values of the same data type. They are defined with a specific size, which determines how many elements they can hold.

• Example:

  int arr[5] = {1, 2, 3, 4, 5}; // An array of integers with 5 elements.

Multidimensional Arrays

Multidimensional arrays are arrays with more than one dimension, allowing for the representation of matrices or tables.

• Example:

  int matrix[3][3] = {
      {1, 2, 3}, 
      {4, 5, 6}, 
      {7, 8, 9}
  }; // A 3x3 matrix of integers.

Passing Arrays to Functions

Arrays can be passed to functions for processing, allowing for the manipulation of multiple values without needing to return them individually.

• Example:

  void printArray(int arr[], int size) {
      for (int i = 0; i < size; i++) {
          printf("%d", arr[i]); // Prints each element of the array.
      }
  }

Arrays and Strings

In C, strings are treated as arrays of characters. A string is a character array that ends with a null character ('\0').

• Defining a String:

  char str[10] = "Hello"; // An array of characters.

• String Functions: Common functions to manipulate strings include:

  • strlen(): Returns the length of the string.
  • strcpy(): Copies one string to another.
  • strcat(): Concatenates two strings.
  • strcmp(): Compares two strings.

• Example:

  char str1[20], str2[20];
  strcpy(str1, "Hello");
  strcat(str1, " World");
  printf("%s", str1); // Outputs: Hello World