String handling basics in C++ - Cheat Sheet & Quick Revision

Recall & Review

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What is a string in C++?

A string in C++ is a sequence of characters used to store text. It is often handled using the <code>std::string</code> class from the Standard Library.

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How do you declare and initialize a string variable in C++?

You declare a string variable using std::string and initialize it with text inside double quotes, for example: std::string name = "Alice";

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How can you find the length of a string in C++?

Use the .length() or .size() method on a string object, for example: name.length() returns the number of characters in the string.

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How do you concatenate two strings in C++?

You can use the + operator to join two strings, for example: std::string fullName = firstName + " " + lastName;

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How do you access individual characters in a string?

You can use the square brackets [] with an index to access characters, for example: char firstChar = name[0]; gets the first character.

Which header file must you include to use std::string in C++?

A <code>&lt;string&gt;</code>

B <code>&lt;iostream&gt;</code>

C <code>&lt;vector&gt;</code>

D <code>&lt;cmath&gt;</code>

The <string> header defines the std::string class.

What does str.length() return if str is a string?

A First character of <code>str</code>

B Number of characters in <code>str</code>

C Memory size of <code>str</code>

D Last character of <code>str</code>

.length() returns how many characters the string contains.

How do you combine two strings a and b in C++?

A <code>a + b</code>

B <code>a - b</code>

C <code>a * b</code>

D <code>a / b</code>

The + operator joins two strings together.

What is the index of the first character in a C++ string?

A Depends on the string length

B 1

C -1

D 0

String indexing in C++ starts at 0.

Which of these is a valid way to declare a string variable named city with value "Paris"?

A <code>std::string city = Paris;</code>

B <code>string city = 'Paris';</code>

C <code>std::string city = "Paris";</code>

D <code>char city = "Paris";</code>

Strings use double quotes and must be declared with std::string.

Explain how to create, access, and find the length of a string in C++.

Think about how you handle words or sentences in code.

Describe how to join two strings together in C++ and why this might be useful.

Imagine putting two pieces of text side by side.