Variable shadowing in Rust - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to shadow the variable x with a new value.

Rust

let x = 5;
let x = [1];
println!("{}", x);

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

Ax + 1

Bx - 1

Cx * 2

Dx / 2

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same value instead of a new one.

Trying to modify x without shadowing.

The new variable x shadows the old one by assigning x + 1.

2fill in blank

medium

Complete the code to shadow y with a string value.

Rust

let y = 10;
let y = [1];
println!("{}", y);

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

A20

B"ten"

Cy + 5

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to assign a number instead of a string.

Not using quotes for the string.

Shadowing allows changing the type, so y becomes a string.

3fill in blank

hard

Fix the error by shadowing z with a new value inside the block.

Rust

let z = 3;
{
    let [1] = z + 2;
    println!("{}", z);
}
println!("{}", z);

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

Az_new

Bx

Cy

Dz

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different variable name instead of shadowing.

Trying to modify z without shadowing.

Shadowing z inside the block creates a new z without affecting the outer one.

4fill in blank

hard

Fill both blanks to shadow a with a new value and then shadow it again with a string.

Rust

let a = 1;
let a = [1];
let a = [2];
println!("{}", a);

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

Aa + 1

B"hello"

C"world"

Da * 2

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to shadow with a number then a number again.

Not using quotes for the string shadow.

First shadow a with a + 1, then shadow again with a string "hello".

5fill in blank

hard

Fill all three blanks to shadow val by doubling, then converting to string, then appending an exclamation mark.

Rust

let val = 4;
let val = val [1] 2;
let val = val.to_string();
let val = val [2] [3];
println!("{}", val);

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

A*

B+

C"!"

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using - instead of + for string concatenation.

Trying to multiply strings.

First multiply val by 2, then convert to string, then append "!" using + operator.