7.2. string variables

You can create a variable with type string in the usual ways.

In the code below, the first line creates a string without giving it a value. The second line assigns it the string value "Hello,". The third line is a combined declaration and assignment, also called an initialization.

std::string first;
first = "Hello, ";
std::string second = "world.";

Normally when string values like "Hello, " or "world." appear, they are treated as C strings. In this case, when we assign them to an string variable, they are converted automatically to string values.

We can output strings in the usual way:

cout << first << second << '\n';

In order to compile this code, you will have to include the header file containing the string definitions to all your source files that refer to the string type.

Run the active code below!

Outputting a string variable

#include <iostream>
#include <string>

int main() {
    std::string first;
    first = "Hello, ";
    std::string second = "world.";
    std::cout << first << second << '\n';
}

Q1

Construct a block of code that correctly prints out a string variable.

1. std::cout << x << '\n';

   ↑ ↓ ← → ✓ Use

2. std::string x;

   ↑ ↓ ← → ✓ Use

3. x = "It is cold outside!";

   ↑ ↓ ← → ✓ Use

4. x = "It is cold outside"

   ↑ ↓ ← → ✓ Use

Check answer

Q2

How would you initialize a string?

string x = "Hello";

This is the correct way to initialize a string.

x = "Hello";

This is an assignment.

string x;

This is a declaration.

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Q3

Click on each spot where a string assignment occurs.

int main() {
    string fruit;
    fruit = "apple";
    fruit = "pear";
    string flavor = "sweet";
    flavor = "vanilla";
}

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