Unit4ArrayandStringpptx__2024_09_30_13_15_25

Marwadi University Department of FOT 01CE0101 - Computer Programming Unit - 4 Array and String

Arrays

• Definition: An array is a collection of data items of the same type, accessed with a common name.

  • Data Structure: Holds a finite sequential collection of homogeneous data.

Characteristics of Arrays

• Collection: An array acts as a container for a collection of data.

• Finite: The number of data items in an array is determined before use and is always finite.

• Sequential: Data in the array is stored sequentially in memory.

• Homogeneous: All data items in an array must share the same data type.

Examples of Arrays

• List of customers and their phone numbers.

• Table of daily rainfall data.

• List of employees in an organization.

• Test scores of a class of students.

Declaration of Arrays

• Syntax: type arrayName[arraySize];

• Examples:

  • int group[10];

  • float height[50];

  • char name[15];

Initialization of Arrays

• After declaring an array, its elements must be initialized.

• Static Initialization: Initialize during declaration.

• Dynamic Initialization: Initialize elements during program execution.

Static Initialization

• Defined using curly braces with values separated by commas.

  • Example: int marks[5] = {90, 86, 89, 76, 91};

Dynamic Initialization

• Assign values to an array element during execution using the following syntax:

  • Syntax: array_name[index] = some_value;

  • Example: scanf("%d", &arr[i]);

Advantages and Disadvantages of Arrays

• Advantages:

  • Less lines of code for multiple elements.

  • Random access using array index.

  • Easy access and traversal of elements.

  • Simplified sorting.

• Disadvantages:

  • Costly insertion and deletion due to memory management.

  • Fixed size defined at declaration; not dynamic like linked lists.

One-Dimensional Arrays

• Syntax: datatype array_name[size];

• Example: Declaration and access examples provided.

Accessing Elements of an Array

• Specify array name followed by an index inside square brackets. Index starts at 0.

• Example:

  • int a[5];

  • Elements: a[0], a[1], ... a[4]

Two-Dimensional Arrays in C

• A simplest form of multidimensional array, defined as an array of arrays.

• Organized as matrices (rows and columns) for bulk data processing.

Declaration of Two-Dimensional Arrays

• Syntax: datatype array_name[rows][columns];

• Example: Can be declared with the type and size of rows and columns.

Initializing Two-Dimensional Arrays

• Two methods: conventional and better method using nested braces.

  • Example: int x[3][4] = {{0, 1, 2, 3}, {4, 5, 6, 7}, {8, 9, 10, 11}};

Matrix Operations Using Arrays

• Definition: A matrix is a grid-like storage format that organizes data in rows and columns.

• Basic operations include addition, subtraction, and multiplication along with user-defined orders.

Matrix Multiplication Algorithm

1. Start Program.

2. Enter rows and columns of matrices.

3. Input elements for both matrices.

4. Perform multiplication and store in a third matrix.

5. Print final matrix.

Strings in C

• Definition: Sequence of characters treated as a single data item, enclosed in double quotes. Example: "You are the best."

Declaration of Strings

• Strings are declared as character arrays.

• Syntax: char string-name[size];

Initializing String Variables

• Strings are null-terminated; anything after is ignored.

  • Example: char str[20] = "Initial value";

Common String Handling Functions

• Functions included in string.h:

  • strlen(): Returns length, excluding null character.

  • strcpy(): Copies source string to destination.

  • strcmp(): Compares two strings.

  • strcat(): Concatenates two strings.

  • strrev(): Reverses the string.

  • strlwr(): Converts string to lowercase.

  • strupr(): Converts string to uppercase.

  • strstr(): Returns pointer to a substring.

Example Program for String Functions

• Demonstrates the use of several string functions in C like length, reverse, concatenation, and comparison.

Conclusion

• Understanding arrays and strings is fundamental in programming with C, enabling structured data storage and manipulation.