Arrays and Strings Quiz

Arrays and Strings

• Arrays: A collection of the same data type stored in contiguous memory locations.
• Efficient for storing and accessing data.
• Example: Storing marks of six subjects. Instead of declaring six variables, a single array variable (e.g., marks) can store all marks in contiguous locations.
• Array elements: Each element is accessed using an index (integer value). The first element has index 0.
• Index: The position of an element within the array.
• Size of array: The number of elements.
• Index range: From 0 up to size - 1.
• Declaration: Specifies the data type of elements, array name, and size: datatype arrayname[arraysize].
• Example: int marks[6]. This declares an integer array named marks that can hold 6 integers.
• Initialization: Values can be assigned during declaration: int marks[6]={45, 67, 50, 79, 58, 36};

Array Initialization

• Initialization in Declaration: Array elements can be initialized directly in the declaration.

• Compiler Determination: The compiler determines the size of the array by counting the values in the initializer list. It is not necessary to explicitly define size if you initialize all elements.

• Example: int marks[] = {45, 67, 50, 79, 58, 36}; is equivalent to writing out the assignment for each element.

sizeof() Function

• Purpose: Determines the number of bytes occupied by a data type.
• Usage: Used within parentheses and is a function that can determine size of int, float, double, char, etc.

Two-Dimensional Arrays

• Purpose: Store data in a table-like structure (rows and columns).
• Declaration: datatype arrayname[rowSize][colSize].
• Indices: Row and column indices are used to access individual elements (e.g., k[1][3]=15 accesses element in row 1, column 3).
• Initialization: Similar to one-dimensional arrays, elements can be initialized in the declaration.
• Example float height[8][10];

Accessing and Filling Two-Dimensional Arrays

• Accessing: elements can be accessed row by row or column by column, typically using nested loops.
• Filling: Elements are filled in using nested loops.

Strings

• Nature: A sequence of characters.
• Storage: Stored in a one-dimensional character array.
• Null character: '\0' marks the end of the string.
• Declaration: char stringName[stringSize];
• Size Consideration: The stringSize must be at least one larger than the number of characters in the string to accommodate the null character.
• Initialization: Strings can be initialized in the declaration using a character array or a string literal (e.g., char name[10] = "John";).