One-dimensional arrays in C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a one-dimensional array in C++?

A one-dimensional array in C++ is a collection of elements of the same type stored in contiguous memory locations, accessed by a single index.

beginner

How do you declare a one-dimensional array of 5 integers in C++?

You declare it like this: int arr[5]; which creates an array named arr with 5 integer elements.

beginner

How do you access the third element of an array named arr?

You access it using the index 2: arr[2] because array indexing starts at 0.

intermediate

What happens if you try to access an array element outside its declared size?

Accessing outside the array size leads to undefined behavior, which can cause errors or unexpected results because you read or write memory not allocated for the array.

beginner

How can you initialize a one-dimensional array with values at the time of declaration?

You can initialize it like this: int arr[3] = {10, 20, 30}; which sets the first element to 10, second to 20, and third to 30.

What is the index of the first element in a C++ array?

A 0

B 1

C -1

D Depends on the array size

In C++, array indexing always starts at 0.

Which of the following declares an array of 10 doubles?

A double arr()

B double arr;

C int arr[10];

D double arr[10];

The correct syntax for declaring an array of 10 doubles is double arr[10];.

What will happen if you access arr[5] in an array declared as int arr[5];?

A Undefined behavior

B Returns 0

C Compiler error

D Returns last element

Accessing arr[5] is outside the bounds (valid indices are 0 to 4), causing undefined behavior.

How do you initialize an array with values 1, 2, 3 in C++?

A int arr = {1, 2, 3};

B int arr[3] = {1, 2, 3};

C int arr(3) = {1, 2, 3};

D int arr[] = 1, 2, 3;

The correct way is int arr[3] = {1, 2, 3};.

What type of elements can a one-dimensional array hold?

A Only integers

B Elements of different data types

C Elements of the same data type

D Only characters

Arrays hold elements all of the same data type.

Explain what a one-dimensional array is and how you use it in C++.

Think about a row of boxes where each box holds a value.

Describe how to declare, initialize, and access elements in a one-dimensional array.

Imagine labeling and filling boxes, then picking a box by its number.