Why variables are needed in Rust - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a variable named x with the value 5.

Rust

let [1] = 5;

Drag options to blanks, or click blank then click option'

Avar

B5

Clet

Dx

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number instead of a variable name.

Trying to use var which is not Rust syntax.

In Rust, let declares a variable. Here, x is the variable name.

2fill in blank

medium

Complete the code to print the value of the variable y.

Rust

println!("The value is: {}", [1]);

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A"y"

By

Cprintln!

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Putting the variable name in quotes, which prints the word, not the value.

Using a wrong identifier.

To print the value of a variable, use its name without quotes.

3fill in blank

hard

Fix the error by completing the code to make the variable mutable.

Rust

let [1] counter = 0;

Drag options to blanks, or click blank then click option'

Amut

Bis

Clet

Dvar

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to use var which is not Rust syntax.

Putting mut in the wrong place.

In Rust, mut makes a variable mutable so its value can change.

4fill in blank

hard

Fill both blanks to declare a mutable variable score with value 10 and then increase it by 5.

Rust

let [1] score = 10;
score [2] 5;

Drag options to blanks, or click blank then click option'

Amut

B+=

C=

Dlet

Attempts:

3 left

💡 Hint

Common Mistakes

Using = instead of += which replaces the value.

Not making the variable mutable before changing it.

Use mut to make score mutable and += to add 5 to it.

5fill in blank

hard

Fill all three blanks to declare a variable name with value "Alice", print it, and then change it to "Bob".

Rust

let [1] name = "Alice";
println!("Name: {}", [2]);
name [3] "Bob";

Drag options to blanks, or click blank then click option'

Amut

Bname

C=

Dlet

Attempts:

3 left

💡 Hint

Common Mistakes

Not making the variable mutable before changing it.

Using quotes around the variable name when printing.

Using the wrong operator to change the value.

Make name mutable with mut, print it by its name, and assign a new value with =.