When programs need to manage large collections of data efficiently, arrays become the tool of choice. Similarly, when dealing with text, C provides string handling techniques that allow programmers to manipulate words and characters with ease. This unit introduces the fundamentals of arrays and explains how C handles strings through built-in functions, bridging the gap between raw data storage and meaningful processing.
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Arrays: Organized Data Storage
An array is a collection of elements of the same data type stored in contiguous memory locations. Instead of declaring multiple variables for related data, arrays allow programmers to manage them under a single name with indexing.
One-Dimensional Arrays
Represented as a simple list of elements.
Example:
int marks[5];stores five integer values like student marks.Accessed using index values such as
marks[0],marks[1], etc.
They are widely used for linear data storage like scores, salaries, or temperatures.
Two-Dimensional Arrays
Often visualized as a table or matrix.
Example:
int matrix[3][3];stores 9 values in 3 rows and 3 columns.Ideal for mathematical operations, grids, or tabular data.
Multidimensional Arrays
Extend beyond two dimensions to represent more complex structures.
Example:
int cube[3][3][3];can represent 3D data.Used in simulations, scientific calculations, and image processing.
Arrays thus provide a structured and efficient approach to handling data, making programs more compact and manageable.
Strings: Character Arrays with Purpose
In C, there is no distinct data type for strings — instead, strings are stored as character arrays terminated by a special null character '\0'.
Character Arrays vs. String Literals
Character Array: Defined as
char name[10] = {'J','o','h','n','\0'};— gives full control but requires manual termination.String Literal: Defined as
char name[] = "John";— automatically includes the null terminator.
While character arrays provide flexibility, string literals are simpler and widely preferred for everyday programming tasks.
String Handling Functions in C
C provides a set of standard library functions (declared in <string.h>) for string manipulation, eliminating the need to manually handle each character.
Commonly Used Functions
strlen(str)→ Returns the length of the string (excluding\0).strcpy(dest, src)→ Copies one string into another.strcmp(str1, str2)→ Compares two strings; returns 0 if equal.strcat(dest, src)→ Concatenates (joins) two strings.
These functions allow programmers to process text efficiently, whether checking passwords, sorting names, or building sentences dynamically.
Why Arrays and Strings Matter
Arrays provide a foundation for organized data storage, while string handling transforms simple characters into meaningful text processing. From databases storing customer names to operating systems managing file paths, these concepts are everywhere in computing.
Mastering arrays and strings not only strengthens a programmer’s logical thinking but also prepares them for advanced topics like pointers, dynamic memory allocation, and data structures in later units.