Mutable Variables

Declaring and manipulating variables in programming is a fundamental concept that allows you to store and modify data. Variables in Rust are immutable by default, but you can make them mutable using the mut keyword.

In this challenge, you will declare and use mutable variables in Rust. You will be given a function where you need to declare variables, modify their values, and perform specific operations.

Your task

Declare variable text with any initial value of type String Use let mut to make it mutable.
Re assign the variable text to something else of your choice.
Call the mutates_value(&mut text) function, which will change the value of your text variable.
Return the final value of the variable.

Hints

If you're stuck, feel free to check out the hints below

Click here to see the hints

Use the let mut keyword to declare a mutable variable.
To give the value to as a mutable reference use the &mut keyword. e.g.
```
let mut text = "hello";
mutates_value(&mut text);
```
To create a String from a &str, use String::from(value) or value.to_string(). e.g.
```
let text = "hello";
let text = text.to_string();
```

To return a value from a function, either use the return statement or let the last expression be the return value. For example:

// Using return statement
fn example1() -> String {
    return String::from("hello");
}
 
// Using expression (no semicolon)
fn example2() -> String {
    String::from("hello")
}

Editor not available on Mobile!

In order to solve the challenge, please visit this page on a desktop computer.

Solutions

maomao9-0

2 hours ago

2.84ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    // 2. Call `mutates_value` with a mutable reference to `text`
    // 3. Return the value of `text` as a String
    let mut text = "hello".to_string();
    mutates_value(&mut text);
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

srushti335

8 hours ago

2.94ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text:String = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Leo

leyonh

9 hours ago

3.30ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("value");
    mutates_value(&mut text);
    return text
    // 2. Call `mutates_value` with a mutable reference to `text`
    // 3. Return the value of `text` as a String
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

amupxm

13 hours ago

3.38ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye");
}

Augsorn Chanklad

up2code

a day ago

3.44ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text.to_string();
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Tpel917

2 days ago

4.36ms

81.28kb

pub fn mutating_variables() -> String {
    let mut text = String::from("hello");
    mutates_value(&mut text);
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

0xfave

3 days ago

3.37ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

ohmurphy

3 days ago

3.75ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("bye");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

___

justcode-28

3 days ago

3.25ms

81.28kb

pub fn mutating_variables() -> String {
    let mut text = String::from("hello");
    mutates_value(&mut text);
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

onigiri-w2

3 days ago

4.57ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text.to_string()
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}
fn main() {
    // 4. Call `mutating_variables` and print the result
    let result = mutating_variables();
    println!("{}", result);
}

anhdoo

TuanAnhDoHoang

3 days ago

3.46ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    String::from(text)
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Kevin

Caoimhin89

4 days ago

3.65ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text.to_string()
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

TomnomTom96

4 days ago

3.20ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

lamjabog

5 days ago

3.14ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

ShiLu1211

5 days ago

3.51ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    // 2. Call `mutates_value` with a mutable reference to `text`
    // 3. Return the value of `text` as a String
    let mut text = "hello".to_string();
    text = "qc".to_string();
    mutates_value(&mut text);
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Miguel Fernandez

mafdezmoreno

6 days ago

3.24ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut hello_str = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut hello_str);
    // 3. Return the value of `text` as a String
    return hello_str;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Miguel Fernandez

mafdezmoreno

6 days ago

3.29ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut hello_str = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut hello_str);
    // 3. Return the value of `text` as a String
    return hello_str;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

NeoPlayer

Neoplayer

6 days ago

4.24ms

81.28kb

pub fn mutating_variables() -> String {
    let mut text = "hello".to_string();
    mutates_value(&mut text);
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

koala-ru

6 days ago

4.16ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    
    
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value( &mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

yuzvdp

6 days ago

3.34ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Stas

nevmstas

6 days ago

4.73ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    // 2. Call `mutates_value` with a mutable reference to `text`
    // 3. Return the value of `text` as a String
    let mut text: String = "hello".to_string();
    
    mutates_value(&mut text);
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

J. Sassen

JSG-GIT

7 days ago

3.48ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Tristan Young

DragonBeast829

7 days ago

4.13ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Alejandro Roigé

roigecode

7 days ago

3.34ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Kenas Zogara

kenaszogara

7 days ago

3.35ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

albertjke

8 days ago

3.46ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return String::from(text);
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Mehben

8 days ago

3.67ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let text = "hello";
    let mut text = text.to_string();
    mutates_value(&mut text);
    return String::from(text);
    // 2. Call `mutates_value` with a mutable reference to `text`
    // 3. Return the value of `text` as a String
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Patrick Steinhardt

pks-t

8 days ago

2.80ms

81.28kb

pub fn mutating_variables() -> String {
    let mut input = String::from("foobar");
    mutates_value(&mut input);
    input
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Danny Krämer

d9r-dev

8 days ago

3.40ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Zhen-Lun (Kevin) Hong

kevinhongzl

8 days ago

3.57ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Kanak Shilledar

kanakshilledar

8 days ago

4.45ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Seth Wood

seth-wood

9 days ago

2.82ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    // 2. Call `mutates_value` with a mutable reference to `text`
    // 3. Return the value of `text` as a String
    let mut text = String::from("hello");
    mutates_value(&mut text);
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Octavian

orouwk

9 days ago

6.45ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

An Nguyen The

anthanh17

9 days ago

2.94ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

KK

khekrn

10 days ago

4.83ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("hello");
    mutates_value(&mut text);
    return text;
    // 2. Call `mutates_value` with a mutable reference to `text`
    // 3. Return the value of `text` as a String
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Alexandr

Aoxomoxoa

11 days ago

6.02ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text.to_string()
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Pedro Diaz

pdiaz

11 days ago

3.70ms

81.28kb

pub fn mutating_variables() -> String {
    let mut text = "hello".to_string();
    mutates_value(&mut text);
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

zazapalm3012

11 days ago

3.97ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Gurneet singh

GS-Jatt

11 days ago

3.86ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    // 2. Call `mutates_value` with a mutable reference to `text`
    // 3. Return the value of `text` as a String
let mut text = "hello".to_string();
mutates_value( & mut text);
text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

ishmeals

12 days ago

3.37ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text : String = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Emon

emon805

12 days ago

4.06ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text= String:: from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Teimur Gasanov

teimurjan

12 days ago

3.65ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Artur Kaminski

DevArtK

13 days ago

4.32ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

LLukeDB

13 days ago

4.19ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Paul T

DeveloperPaul123

13 days ago

9.09ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Tony Gonzales

Hominine

13 days ago

3.40ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
   let mut text = String::from("hello"); 
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text); 
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Prajwal Adhikari

Prajwal-Adhikari

13 days ago

3.82ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("helllo");
    
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Prajwal Adhikari

Prajwal-Adhikari

13 days ago

3.75ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("helllo");
    
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Health-Care-Movie

13 days ago

3.24ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = "hello".to_string();
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Thomastienn

14 days ago

3.25ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    // 2. Call `mutates_value` with a mutable reference to `text`
    mutates_value(&mut text);
    // 3. Return the value of `text` as a String
    return text;
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}