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")
}

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Solutions

Melkzedek Choti

chotixity

an hour ago

4.00ms

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")
}

avk458

2 hours ago

3.35ms

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")
}

iamforgettable

4 hours 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")
}

Corwin Dong

taigua

5 hours ago

5.47ms

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")
}

Esteban Pérez

lep511

7 hours ago

2.76ms

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
    println!("{}", text);
    text.to_string()
    
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Enderson Kruger

endersonkruger

10 hours ago

3.45ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("Olá");
    // 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")
}

Timothy Z.

kKaskak

10 hours ago

2.78ms

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 as String
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Fredo

sakseiw

11 hours ago

3.40ms

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")
}

cmdrtomalak

12 hours ago

3.42ms

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

RiyadDz22

12 hours ago

4.44ms

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

manuelmj

12 hours ago

3.17ms

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

prey169

13 hours ago

8.67ms

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`
    // 3. Return the value of `text` as a String
    mutates_value(&mut text);
    text
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Eduardo Antuña Díez

eduadiez

13 hours ago

3.50ms

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")
}

Swarnim Chandve

Swarnim-Chandve

14 hours ago

2.97ms

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

Sathit Junthong

famesensor

16 hours ago

2.92ms

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

Patrick Yu

PatrickYu17

16 hours ago

3.15ms

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")
}

5ch3m45

16 hours ago

3.81ms

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")
}

christianbaumberger

16 hours 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
    text.to_string()
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Matthew Taylor

mt1379

17 hours ago

3.70ms

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

Tanmay Kulkarni

tanmay-kulkarni

18 hours ago

2.96ms

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")
}

nori

kikakugai

19 hours ago

2.66ms

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")
}

Akif Mehmood

theakifmehmood

19 hours ago

2.98ms

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")
}

Nikita Smirnov

Nismirno

20 hours ago

8.04ms

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")
}

chuyuanlinzi

a day ago

3.20ms

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")
}

studymachine

studymachiney

a day 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")
}

Nyakio Maina

nyakiomaina

a day ago

2.85ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = String::from("hello");
    mutates_value(&mut text);
    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")
}

Nino Marrazzo

iliych91

a day ago

2.93ms

81.28kb

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

Allan Dingwall

allandingwall

a day ago

3.28ms

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")
}

Matis CAFFIAUX

M4ti5

a day ago

3.88ms

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")
}

Toshikazu Fukushima

fukushima-toshi-exnoa

a day ago

2.96ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = String::from("hello");
    // 2. Reassign the value of `text` to a new value
    mutates_value(&mut text);
    // 3. Return the value of `text`
    text
}
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

エヴァンゲリオン

Lu-zihang

a day ago

2.94ms

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")
}

c4e

c4ebt

a day ago

3.71ms

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

Andrew Thomas

ch00kz

a day ago

4.08ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text = "hello".to_owned();
    // 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_owned()
}
// Do not change this function
pub fn mutates_value(value: &mut String) {
    *value = String::from("bye")
}

Douglas Campbell

CampbellD84

a day ago

5.19ms

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")
}

wphan

a day ago

5.71ms

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

Taufik Hidayat

tfkhdyt

a day ago

2.99ms

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")
}

Evans Kojo Kwofie

0papi

a day ago

3.47ms

81.28kb

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

krumbthi

Krumbthi

a day ago

2.64ms

81.28kb

pub fn mutating_variables() -> String {
    // 1. Declare a mutable variable `text` with value "hello"
    let mut text: String = "hello".into();
    // 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")
}

Sobornost

sobornostea

a day ago

3.30ms

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")
}

Levent Can Yılmaz

lvntcnylmz

a day ago

2.85ms

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")
}

André Decher

Wolfy7

2 days ago

3.59ms

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")
}

Paul Pavlov

ppavlovdev

2 days ago

3.25ms

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

Manu

wirew0lf

2 days ago

2.73ms

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")
}

Danny Burnett

danjambur

2 days ago

3.00ms

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")
}

Ruud Erie

ruuderie

2 days ago

2.82ms

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);
    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")
}

Sahaj Ramachandran

SahajR

2 days ago

2.98ms

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")
}

Matt Simpson

msmps

2 days ago

3.89ms

81.28kb

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

Angel Echavarria

ames89

2 days ago

2.84ms

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")
}

Marc Delvaux

mdelvaux

2 days ago

2.86ms

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")
}

Donald Huber-Youmans

dHuberYoumans

2 days ago

2.56ms

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")
}