C Programming Module 7: Arrays
48 Questions
20 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a single-dimensional array used for?

  • Storing values in non-contiguous memory locations
  • Storing a single value at a time
  • Storing a list of values of the same data type (correct)
  • Storing multiple values of different data types

How should a single-dimensional array be declared in C?

  • Only by specifying the data type
  • By using a predefined constant as the size
  • By defining both the data type and the size of the array (correct)
  • Using dynamic memory allocation only

What is the benefit of using a constant for the array size?

  • It provides a predefined limit that can enhance code readability (correct)
  • It allows multiple data types to be stored in the array
  • It simplifies the syntax of array declaration
  • It makes array resizing easier during execution

Where are the elements of a single-dimensional array stored in memory?

<p>In contiguous memory locations (D)</p> Signup and view all the answers

Which of the following is an example of correctly defining a single-dimensional array with a constant?

<p>#define SIZE 50; int arr[SIZE]; (A)</p> Signup and view all the answers

What is the purpose of the given for loop in the context provided?

<p>To find the maximum value in the array. (A)</p> Signup and view all the answers

What will happen if an index exceeding the declared size of an array is accessed?

<p>The program will compile but may lead to undefined behavior. (B)</p> Signup and view all the answers

What characteristic differentiates arrays from scalar variables?

<p>Arrays can store multiple values in a single structure (B)</p> Signup and view all the answers

How can a two-dimensional array be initialized in C?

<p>By listing values row-by-row within braces. (D)</p> Signup and view all the answers

Which function can be used to read values into an array from user input?

<p>scanf() (B)</p> Signup and view all the answers

In what scenario is it preferable to use arrays instead of scalar variables?

<p>When managing a collection of multiple related values (B)</p> Signup and view all the answers

How does the C programming language treat array indices?

<p>C does not perform index-bound checks. (C)</p> Signup and view all the answers

What must be specified when passing a two-dimensional array to a function in C?

<p>The column size must be specified, but the row size can be omitted. (B)</p> Signup and view all the answers

Which statement about multidimensional arrays is true?

<p>They can be used to store more complex data structures (D)</p> Signup and view all the answers

Which of the following correctly represents a one-dimensional array declaration for integers in C?

<p>int grades[5]; (C)</p> Signup and view all the answers

What is the output statement for displaying the value at a specific index in an array?

<p>printf(&quot;Value at index %d: %d&quot;, i, grades[i]); (B)</p> Signup and view all the answers

What is the storage allocation for a one-dimensional array of doubles declared as 'double prices[6];'?

<p>Allocates space for 6 doubles. (B)</p> Signup and view all the answers

Which statement about the initialization of array elements is true?

<p>Individual elements can be set using individual assignments or via scanf(). (B)</p> Signup and view all the answers

In the context of the provided output example, what are users prompted to do?

<p>Enter grades for storage in an array. (B)</p> Signup and view all the answers

Which statement about two-dimensional arrays is true regarding braces in initialization?

<p>Inner braces can be omitted while keeping the outer braces. (C)</p> Signup and view all the answers

What type of data can be stored in an array declared as 'char code[4];'?

<p>Up to four characters. (C)</p> Signup and view all the answers

What is the result of the following code snippet: max = price[i];?

<p>Assigns the current value of price[i] to maximum. (B)</p> Signup and view all the answers

How is the array 'int vals[3][2]' initialized if written as 'int vals[3][2] = {1, 2, 3, 4, 5, 6};'?

<p>It creates a 3x2 array with values based on row-wise order. (C)</p> Signup and view all the answers

What does the one-dimensional array declaration 'float amount[100];' represent?

<p>An array that can store up to 100 floating-point values. (C)</p> Signup and view all the answers

What is the main characteristic of global arrays?

<p>They are declared outside a function and retain values until main() finishes executing. (C)</p> Signup and view all the answers

Which statement about static local arrays is true?

<p>They retain their values for the duration of the program's execution. (A)</p> Signup and view all the answers

What happens to automatic local arrays when a function is called?

<p>They are created and destroyed with each function call. (C)</p> Signup and view all the answers

Which of the following is NOT true regarding the initialization of static local arrays?

<p>They must be explicitly initialized. (C)</p> Signup and view all the answers

How is memory allocated for automatic local arrays?

<p>On the stack for each function call. (B)</p> Signup and view all the answers

Which of the following best describes the life cycle of a static local array?

<p>Created once and remains until the program terminates. (B)</p> Signup and view all the answers

What differentiates automatic local arrays from static local arrays?

<p>Automatic local arrays are destroyed and recreated each time the function is called. (C)</p> Signup and view all the answers

What is a key feature of global arrays in terms of memory retention?

<p>They retain values between different function calls. (C)</p> Signup and view all the answers

What occurs when a character array is initialized with a string literal?

<p>Each character is assigned to consecutive array elements with a null terminator added. (A)</p> Signup and view all the answers

What is the effect of passing an individual array element to a function?

<p>The function receives a copy of the element passed by value. (D)</p> Signup and view all the answers

What is a key difference between declaring a character array with and without size specifications but using initializers?

<p>Both methods result in the same size for the array. (B)</p> Signup and view all the answers

Which of the following declarations is equivalent to char codes[] = "sample"?

<p>char codes[] = {'s', 'a', 'm', 'p', 'l', 'e'}; (A)</p> Signup and view all the answers

What will happen if you try to access an array element out of its declared bounds?

<p>Undefined behavior may occur, potentially causing errors. (C)</p> Signup and view all the answers

Why is it unnecessary to specify the size when initializing an array with an initializer list?

<p>The size is always automatically inferred from the initial values. (B)</p> Signup and view all the answers

When passing an array to a function in a programming language, what is typically passed?

<p>A pointer to the first element of the array. (A)</p> Signup and view all the answers

What syntactic form can simplify initializing character arrays?

<p>Omitting braces and commas when using string literals. (A)</p> Signup and view all the answers

What happens when an entire array is passed to a function by reference?

<p>The function can modify the original array elements. (B)</p> Signup and view all the answers

Why is it generally advisable to omit the size of the array in the function header?

<p>To simplify the function signature. (B)</p> Signup and view all the answers

What could be a consequence of making duplicate copies of large arrays during function calls?

<p>It consumes more execution time and storage. (D)</p> Signup and view all the answers

Which statement accurately reflects passing arrays to functions?

<p>Passing arrays is often simpler than passing individual elements. (A)</p> Signup and view all the answers

In the example findMax(grades);, what is being passed to the function?

<p>A reference to the original grades array. (C)</p> Signup and view all the answers

What is one advantage of passing the entire array rather than individual elements?

<p>It allows for easier tracking of changes made inside the function. (C)</p> Signup and view all the answers

What is a reason why passing the entire array by reference is preferred in many cases?

<p>It conserves memory and optimizes performance. (B)</p> Signup and view all the answers

What is a potential drawback of passing individual elements instead of an entire array?

<p>It increases the complexity of modifications made inside the function. (B)</p> Signup and view all the answers

Flashcards

One-Dimensional Array

An array that stores a list of values of the same data type in contiguous memory locations.

Scalar Variable

A variable that can store only one value at a time.

Array Declaration

Declaring an array involves specifying the data type and the size of the array.

Array Size

The number of values an array can hold.

Signup and view all the flashcards

Contiguous Memory

Memory locations stored one after another in a sequence.

Signup and view all the flashcards

Array Initialization

Giving initial values to the array elements.

Signup and view all the flashcards

Constant for Array Size

Using a constant to represent the size of the array.

Signup and view all the flashcards

Data Type

The type of values to be stored in the array elements.

Signup and view all the flashcards

Array element assignment

Assigning values to individual elements of an array using assignment statements or functions like scanf().

Signup and view all the flashcards

Array input with for loop

Using a for loop to input data into an array iteratively, such as asking for various grades.

Signup and view all the flashcards

Array bounds check

C doesn't automatically check array indices for validity.

Signup and view all the flashcards

Two-dimensional array initialization

Two-dimensional arrays can be initialized in a row-by-row manner using braces.

Signup and view all the flashcards

Initializing 2D arrays (simplified)

You list values in braces, separating rows with , or {}.

Signup and view all the flashcards

Out-of-bounds index

Using an index that is beyond the valid range defined for the array.

Signup and view all the flashcards

Passing 2D arrays to functions

Pass only the array name to the function. Specify the columns in the parameter.

Signup and view all the flashcards

Finding Maximum Value

Finding the largest element within an array using looping and comparisons.

Signup and view all the flashcards

scanf function

A function used for reading input from the console and storing it in variables or arrays in C.

Signup and view all the flashcards

Array Memory Allocation

Arrays reserve memory when defined.

Signup and view all the flashcards

Output Array Data

Displaying the stored data from the array using functions like printf().

Signup and view all the flashcards

Array initialization (one-dimensional)

List elements separated by commas (or row-wise if using braces) in the declaration block when declaring array variables.

Signup and view all the flashcards

2D array parameter (function)

When passing a 2D array to a function, you need to mention the column size, but you don't need to explicitly mention the row size for it.

Signup and view all the flashcards

Array data type

Arrays hold values with the same data type.

Signup and view all the flashcards

Global Arrays

Arrays declared outside a function.

Signup and view all the flashcards

Local Arrays

Arrays declared inside a function.

Signup and view all the flashcards

Static Local Arrays

Local arrays declared with the static keyword, persist throughout program execution.

Signup and view all the flashcards

Automatic Local Arrays

Local arrays without the static keyword. Created and destroyed with each function call.

Signup and view all the flashcards

Array Initialization (automatic)

Arrays without explicit initialization are automatically initialized to zero.

Signup and view all the flashcards

Array Initialization (explicit)

Arrays initialized with values provided by the programmer.

Signup and view all the flashcards

Static vs. Automatic

Static variables maintain their value throughout the program lifecycle, while automatic variables are created and destroyed for each function call.

Signup and view all the flashcards

Array Lifetime

The duration for which an array exists in memory. It varies depending on whether the array is global or local, and whether it's declared as static.

Signup and view all the flashcards

Passing an Array by Reference

When you pass an entire array to a function, you're actually passing a reference to the original array, not a copy. This allows the function to directly modify the array elements, and those changes will persist outside the function.

Signup and view all the flashcards

Why Passing by Reference for Arrays?

Passing an array by reference is more efficient than making a copy of the array for each function call, especially with large arrays. Copying consumes storage and execution time, and can be frustrating when trying to return changes made to multiple elements.

Signup and view all the flashcards

Function Argument: Array Size

When passing an array to a function, you can generally omit the size of the array in the function parameter list. It's not strictly necessary.

Signup and view all the flashcards

Array Modification in Function

Changes made to array elements within a function will affect the original array if the array was passed by reference. This behavior provides flexibility in modifying data.

Signup and view all the flashcards

Two-Dimensional Arrays

A two-dimensional array is essentially an array of arrays, where each element is itself an array. These arrays represent data organized in a tabular format, with rows and columns.

Signup and view all the flashcards

Accessing Elements in 2D Arrays

Accessing individual elements in a 2D array involves specifying both the row and column index. This is like accessing a specific cell in a spreadsheet.

Signup and view all the flashcards

Example: 2D Array Declaration

Let's say you want to represent a 5x5 grid. A 2D array declaration for this would look like int myArray[5][5];.

Signup and view all the flashcards

2D Array Application

Two-dimensional arrays are often used to represent data in a tabular form, like storing a game board, representing a grid, or handling image data.

Signup and view all the flashcards

Omitting Array Size

You can skip specifying the array size when you directly initialize it with values. The compiler will automatically determine the size based on the number of values in the initializer list.

Signup and view all the flashcards

Character Array Simplification

Initialising a character array with a string literal is simpler than using individual characters. You can directly assign the string and the compiler automatically adds a null terminator ('\0') at the end.

Signup and view all the flashcards

Passing Array Elements by Value

When you pass individual array elements to a function, the function receives a copy of those elements, not the original array. Any changes made to the elements within the function do not affect the original array.

Signup and view all the flashcards

What's the function's perspective on array elements?

When you send an array element to a function, the function doesn't know it's part of a larger array. It treats it as a single, independent value.

Signup and view all the flashcards

How do you access elements in an array?

You can access each element in an array using its index number. The index starts from 0 for the first element, 1 for the second, and so on.

Signup and view all the flashcards

Why is a null terminator important?

The null terminator ('\0') marks the end of a string in a character array. This allows functions that work with strings to know when to stop.

Signup and view all the flashcards

What are the advantages of array initialization with a string literal?

It's more concise and easier to read. You don't need to list each character individually. The compiler automatically adds the necessary null terminator.

Signup and view all the flashcards

What is the difference between passing an array element by value and passing the entire array?

Passing an array element by value sends a copy of that single element to the function. Passing the whole array sends the address of the array, allowing the function to directly access and modify the original array.

Signup and view all the flashcards

Study Notes

Module 7: Arrays

  • Arrays are used to store multiple values of the same data type.
  • Unlike scalar variables, which hold a single value, arrays hold a collection of related values.
  • A single-dimensional array is a list of individual items of the same scalar data type.
  • Arrays are stored in contiguous memory locations
  • Elements in an array are accessed by their position (index)
  • The index starts at 0.
  • Arrays can be initialized during declaration.
  • Initializing is done by listing values within braces, separated by commas

Learning Objectives

  • Understand and manipulate arrays in C.

Outline

  • Lesson 7.1: One-Dimensional Arrays
    • Input and Output of Array Values
  • Lesson 7.2: Array Initialization
  • Lesson 7.3: Arrays as Function Arguments
  • Lesson 7.4: Two-Dimensional Arrays

Overview

  • Scalar variables store a single value at a time. A scalar is an atomic type, which can't be subdivided. A set of values of the same data type can be logically grouped
  • Arrays are a collection of values of the same data type
  • Single-dimensional arrays organize and store data.
  • Multi-dimensional arrays are also studied and how to declare and use such arrays.

Summary: Single-Dimensional Array

  • Data structure to store a list of values of the same data type
  • Declared by specifying the data type and the size.
  • Example: int num [100]. This creates an integer array of size 100.
  • Use constants for array size to avoid retyping.
    • Example: #define MAXSIZE 100, then int num [MAXSIZE].

Summary: Single-Dimensional Array (Continued)

  • Array elements are stored in consecutive memory locations
  • Elements are accessed through their index.
  • Example: num[22].
  • Subscripts start at 0 (the first element), following sequentially upwards.
  • Arrays can be initialized during declaration:
  • Example: int nums[] = {3, 7, 8, 15};

Summary: Single-Dimensional Array (Continued)

  • Arrays are passed to functions by passing their name as an argument.
  • The function receives the address of the first array element(not a copy), ensuring modifications made to array elements affect original
  • Size of the array can be omitted in function parameters.

Summary: Two-Dimensional Arrays

  • Declared by specifying both row and column sizes
  • Example: int mat [ROWS][COLS] ,where ROWS is the number of rows and COLS the number of columns.
  • Can be initialized during declaration, with values listed row by row within braces, separated by commas;
  • Example: int vals[ROWS][COLS] = { {1, 2}, {3,4}, {5, 6} };.

Summary: Two-Dimensional Arrays (Continued)

  • Arrays are passed to functions by passing the array name as an argument.
  • The row size can sometimes be omitted from the parameter declaration but, the column size must still be specified.
  • Arrays are stored in row-wise order in memory

Lesson 7.1: One-Dimensional Arrays

  • Arrays, in C, are collections of values of the same data type.
  • Each array element is stored in contiguous memory locations
  • Elements can be accessed based on their index.
  • In C, elements are accessed using their position/index, using brackets.

Input and Output of Array Values

  • Array elements can be assigned values using individual assignment statements, or through scanf() function.
    • Example: price [5] = 10.69 ;
    • Example: scanf (“%d %lf”, &grades[0], &price[2] )
  • For input, use for statements to loop through the array for interactive entry of values.

Input and Output of Array Values (Continued)

  • for statement used for accessing and displaying array elements and performing operations such as adding up elements.
  • In C, array indices can't be checked by the compiler.
  • You need to be careful with the bounds of an array to avoid errors.

Lesson 7.2: Array Initialization

  • Arrays, like scalar variables, can be declared inside or outside a function.
  • Local arrays - within functions
  • Global Arrays - declared outside functions
  • Static arrays-declared as static. Static arrays retain their values until the program ends.

Lesson 7.2: Array Initialization (Continued)

  • Initializers - values assigned in declarations. They are listed in the order they appear in the array, for example when declaring int grades [5] = {98, 87, 92, 79, 85} ;
  • Whitespace, such as tabs (\t), newlines, (\n), and spaces are ignored by C in initialization.
  • When there are fewer initializers than array elements in declaration, remaining elements are set to 0.
  • Arrays can have their sizes omitted when initialized. The compiler automatically detects the size from the declaration's initializers values.

Lesson 7.2: Array Initialization (Continued)

  • Character arrays - can be initialized with strings omitting the brackets and commas.
  • A \0 is automatically appended to the end of the initializer to mark the end of the string.

Lesson 7.3: Arrays as Function Arguments

  • Passing Individual Array Elements - passing values to functions. Any changes within the function do not affect the original array.
  • Passing the Entire Array - the function receives the original data. Changes inside the function directly affect the original array.

Lesson 7.4: Two-Dimensional Arrays

  • Arrays are tables with rows and columns.
  • Initializations are row-by-row, similar to one-dimensional arrays. The inner braces can be omitted for simplicity.

Lesson 7.4: Two-Dimensional Arrays (Continued)

  • Passing 2D arrays to functions works similarly to 1D arrays; passing a reference (not a copy) to the whole array allows direct modifications to the original array in the function.

Assignment 4

  • Practical uses of 1D arrays: storing lists of grades, prices of items, etc.
  • Explain reasoning.
  • Practical uses of 2D arrays: storing game boards, spreadsheet data, etc.
  • Explain reasoning.
  • Important considerations regarding plagiarism.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

CSIT 102 - 07 Arrays PDF

Description

This quiz covers Module 7 of C Programming, focusing on arrays. Learn how to handle single-dimensional and two-dimensional arrays, understand array initialization, and pass arrays as function arguments. Mastering these concepts is essential for effective programming in C.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser