Character arrays in C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a character array in C++?

A character array is a sequence of characters stored in contiguous memory locations. It is used to store text or strings in C++.

beginner

How do you declare a character array to hold the word "hello"?

You declare it like this: <br> char word[6] = {'h', 'e', 'l', 'l', 'o', '\0'}; <br> The extra '\0' is the null terminator to mark the end of the string.

beginner

Why is the null terminator '\0' important in character arrays?

The null terminator '\0' tells C++ where the string ends. Without it, functions that work with strings may read beyond the array, causing errors.

beginner

How can you initialize a character array with a string literal?

You can write: <br> char greeting[] = "hello"; <br> This automatically adds the null terminator and sets the array size to 6.

intermediate

What happens if you forget to add the null terminator in a character array?

The program may read extra garbage characters after the intended string, causing unexpected behavior or crashes.

What does the '\0' character represent in a character array?

A A newline character

B A space character

C A tab character

D The end of the string

The '\0' character is the null terminator that marks the end of a string in a character array.

How do you declare a character array to hold the word "cat" including the null terminator?

A Both B and C

B char cat[4] = "cat";

C char cat[4] = {'c', 'a', 't', '\0'};

D char cat[3] = {'c', 'a', 't'};

Both B and C correctly declare a character array with the word "cat" and the null terminator.

What is the size of the array when you declare char name[] = "Bob";?

A 3

B 4

C 5

D Depends on compiler

The size is 4 because the string "Bob" has 3 characters plus 1 for the null terminator.

Which of these is NOT a correct way to initialize a character array?

A char arr[] = "hello";

B char arr[6] = {'h', 'e', 'l', 'l', 'o', '\0'};

C char arr[5] = "hello";

D char arr[6] = "hello";

Option C is incorrect because the array size 5 is too small to hold the 5 characters plus the null terminator.

What will happen if you print a character array without a null terminator using std::cout?

A It prints characters until it finds a null terminator, possibly reading garbage

B It prints only the characters in the array

C It causes a compile error

D It prints nothing

Without a null terminator, printing may continue past the array boundary, showing garbage characters.

Explain what a character array is and why the null terminator is important.

Think about how C++ knows where the text ends.

Describe two ways to initialize a character array with the word "dog".

One way uses quotes, the other uses braces.