IT3009 Unit 3: Arrays and Strings Quiz

Basics of Arrays

• An array is a collection of elements of the same data type, accessed via a common variable name.
• Arrays are linear and homogeneous data structures, storing data elements sequentially in memory.
• Each element in an array is identified using an index, starting from zero.
• Example: marks[n-1] refers to the last student's marks in an array named marks.
• Advantages of Arrays:
  • Can store multiple values under a single name.
  • Elements are stored contiguously, allowing efficient access.
  • Supports flexible addition/removal of elements.
• Disadvantages of Arrays:
  • Only accommodates elements of a single data type.
  • A large size can lead to memory consumption without utilization.
  • Difficulties arise in accessing and manipulating multi-dimensional arrays.

Types of Arrays

• Categorized based on dimensions:
  • One-dimensional Arrays
  • Two-dimensional Arrays
  • Multidimensional Arrays

One-dimensional Arrays

• Consist of a single subscript.
• Declaration Syntax:
  data_type array_name[size];
• data_type refers to the data type, array_name is the given name, and size is the maximum number of elements.
• Example:
  float height[20]; (A float array to hold up to 20 elements)

Initialization of One-dimensional Arrays

• Requires initialization to avoid "garbage" values.
• Element-wise initialization:
  array_name[index] = value;
• Complete initialization syntax:
  data_type array_name[size] = {list of values};
• Example:
  int marks[10] = {35, 70, 40, 55, 26, 43, 56, 82, 78, 86};

Character Arrays (Strings)

• Strings are treated as arrays of characters, ending with a null terminator \0.
• Example of declaration:
  char name[10];
• Example of initialization:
  char a[] = {'L', 'E', 'A', 'R', 'N', ' ', 'C', '\0'};

Optional Size in Declaration

• Size can be omitted during declaration, allowing automatic determination of size based on initial values.
• Example:
  int marks[] = {45, 66, 84}; assumes size of 3.

Uninitialized Elements

• Uninitialized array elements default to zero.
• Example:
  int x[5] = {2, 5}; results in [2, 5, 0, 0, 0].

Example Program for One-dimensional Arrays

• Program to find maximum and minimum from 10 numbers:

#include <stdio.h>
int main()
{
    int a[10], i, max, min;
    // Logic for inputting values and finding max/min...
}

• Program structure includes array declaration, loops for input, and conditional checks for determining max and min values.