Rust-Programming-Language/C2/Borrowing/English - Revision history

Madhurig at 11:26, 7 October 2025

2025-10-07T11:26:09Z

Madhurig at 11:25, 7 October 2025

2025-10-07T11:25:28Z

Madhurig at 11:22, 7 October 2025

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Nirmala Venkat at 11:09, 7 October 2025

2025-10-07T11:09:38Z

Nirmala Venkat at 09:55, 26 September 2025

2025-09-26T09:55:38Z

Nirmala Venkat: Created page with "{| border="1" |- || '''Visual Cue''' || '''Narration''' |- || '''Slide 1''' || Welcome to the Spoken Tutorial on
2025-09-26T09:49:03Z

Created page with "{| border="1" |- || '''Visual Cue''' || '''Narration''' |- || '''Slide 1''' || <span style="color:#000000;">Welcome to the Spoken Tutorial on </span><span style="color:#000000..."

New page
{| border="1"
|-
|| '''Visual Cue'''
|| '''Narration'''
|-
|| '''Slide 1'''
|| <span style="color:#000000;">Welcome to the Spoken Tutorial on </span><span style="color:#000000;">'''Borrowing in Rust.'''</span>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">'''Slide 2'''</div>

<div style="color:#000000;">'''Learning Objectives'''</div>
|| In this tutorial, we will learn about:
* <div style="color:#000000;margin-left:1.27cm;margin-right:0cm;">Borrowing and</div>
* <div style="color:#000000;margin-left:1.27cm;margin-right:0cm;">Rules of borrowing</div>

|- style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">'''Slide 3'''</div>

<div style="color:#000000;">'''System Requirements'''</div>
| style="color:#000000;" | To record this tutorial I’m using the follwoing setup
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.101cm;padding-right:0.191cm;"
|| <span style="color:#000000;">'''Slide'''</span><span style="color:#000000;"> </span><span style="color:#000000;">'''5'''</span>

<div style="color:#000000;">'''Code Files'''</div>
||
* <div style="color:#000000;margin-left:1.27cm;margin-right:0cm;">The following code file is required to practise this tutorial.</div>
* <div style="margin-left:1.27cm;margin-right:0cm;"><span style="color:#000000;">This file is provided in the </span><span style="color:#000000;">'''Code Files'''</span><span style="color:#000000;"> link of this tutorial page.</span></div>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.101cm;padding-right:0.191cm;"
|| <div style="color:#000000;">'''Slide 6:'''</div>

<div style="color:#000000;">'''Borrowing'''</div>
|| Let us learn about borrowing.

* <div style="color:#000000;margin-left:1.27cm;margin-right:0cm;">Borrowing is the act of creating references to data without taking ownership</div>
* <div style="color:#000000;margin-left:1.27cm;margin-right:0cm;">When we borrow a value, we reference its memory address with the & </div>

<div style="color:#000000;"></div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.101cm;padding-right:0.191cm;"
|| <div style="color:#000000;">'''Slide 7 : '''</div>

<div style="color:#000000;">'''Borrowing - Example'''</div>

<div style="color:#000000;">fn main() {</div>

<div style="color:#000000;">let s = String::from("hello");</div>

<div style="color:#000000;">let s1 = &s;</div>

<div style="color:#000000;">}</div>
||
* <div style="margin-left:1.27cm;margin-right:0cm;">Here <span style="color:#000000;">‘</span><span style="color:#000000;">'''s’'''</span><span style="color:#000000;"> owns the string “</span><span style="color:#000000;">'''hello'''</span><span style="color:#000000;">”</span></div>
* <div style="margin-left:1.27cm;margin-right:0cm;"><span style="color:#000000;">‘</span><span style="color:#000000;">'''s1'''</span><span style="color:#000000;">’ borrows ‘</span><span style="color:#000000;">'''s'''</span><span style="color:#000000;">’ by reference denoted by </span><span style="color:#000000;">'''&s'''</span><span style="color:#000000;">. </span></div>

<span style="color:#000000;">But </span>ownership<span style="color:#000000;"> of the string is still with </span><span style="color:#000000;">'''s.'''</span>
* <div style="margin-left:1.27cm;margin-right:0cm;"><span style="color:#000000;">'''s1 '''</span><span style="color:#000000;">is only allowed to read the data</span></div>
* <div style="margin-left:1.27cm;margin-right:0cm;"><span style="color:#000000;">It will point to the data, making it an immutable reference to </span><span style="color:#000000;">'''s.'''</span></div>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.101cm;padding-right:0.191cm;"
| style="color:#000000;" |
|| <span style="color:#252525;">Next we will see about rules of borrowing</span><span style="color:#252525;">.</span>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.101cm;padding-right:0.191cm;"
|| '''Slide 8: <span style="color:#000000;">Rules of borrowing:'''</span>

<div style="color:#000000;">1. Any number of Immutable references to a data</div>

||
* <div style="color:#000000;margin-left:1.27cm;margin-right:0cm;">You can have any number of immutable references to a data at the same time.</div>
* <div style="color:#000000;margin-left:1.27cm;margin-right:0cm;">Immutable references do not allow modification of the data.</div>
* <div style="margin-left:1.27cm;margin-right:0cm;"><span style="color:#000000;">Any number of read operations are </span>safe,<span style="color:#000000;"> </span>but <span style="color:#000000;">write </span>operations are not<span style="color:#000000;"> allowed.</span></div>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.101cm;padding-right:0.191cm;"
| style="color:#000000;" |
| style="color:#000000;" | Let us understand with an example.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <span style="color:#000000;">Open </span><span style="color:#000000;">'''Visual'''</span><span style="color:#000000;"> </span><span style="color:#000000;">'''code editor'''</span>
|| <span style="color:#000000;">Open the </span><span style="color:#000000;">'''Visual </span><span style="color:#000000;">S</span><span style="color:#000000;">tudio code editor.'''</span>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <span style="color:#000000;">In the menu bar, click on </span><span style="color:#000000;">'''Terminal'''</span><span style="color:#000000;"> and select</span><span style="color:#000000;">''' New Terminal'''</span><span style="color:#000000;">.</span>

|| <span style="color:#000000;">In the menu bar, click on </span><span style="color:#000000;">'''Terminal'''</span><span style="color:#000000;"> and select</span><span style="color:#000000;">''' New Terminal'''</span><span style="color:#000000;">.</span>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <span style="color:#000000;">'''> cd'''</span><span style="color:#000000;"> </span><span style="color:#000000;">'''Desktop'''</span><span style="color:#000000;">/</span><span style="color:#000000;">'''MyRustProject'''</span>

<span style="color:#000000;">'''>'''</span><span style="color:#000000;"> </span><span style="color:#000000;">'''cargo new borrow'''</span>

<div style="color:#000000;">'''In the menu bar, File >> Open folder >> Desktop >> MyRustProject >> borrow'''</div>
|| <span style="color:#000000;">Let us go to our working directory </span><span style="color:#000000;">'''MyRustProject'''</span><span style="color:#000000;"> as explained earlier.</span>

<span style="color:#000000;">Type the command </span><span style="color:#000000;">'''cargo new borrow '''</span><span style="color:#000000;">and press </span><span style="color:#000000;">'''Enter.'''</span>

<div style="color:#000000;">Open the created project as shown.</div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <span style="color:#000000;">Point to the </span><span style="color:#000000;">'''main.rs'''</span><span style="color:#000000;"> file.</span>

|| <span style="background-color:#ffffff;color:#000000;">In the </span><span style="background-color:#ffffff;color:#000000;">'''main.rs '''</span><span style="background-color:#ffffff;color:#000000;">file, copy and paste the code from the </span><span style="background-color:#ffffff;color:#000000;">'''Code file'''</span><span style="background-color:#ffffff;color:#000000;">.</span>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">fn main() {</div>

<div style="color:#000000;">let a = String::from("Hello world");</div>

<div style="color:#000000;">let b = &a;</div>

<div style="color:#000000;">let c = &a;</div>

<div style="color:#000000;">let d = &a;</div>

<div style="color:#000000;">println!("{}", b);</div>

<div style="color:#000000;">println!("{}", c);</div>

<div style="color:#000000;">println!("{}", d);</div>

<div style="color:#000000;">}</div>
|| <span style="color:#000000;">Variables </span><span style="color:#000000;">'''b, c, d '''</span><span style="color:#000000;">are assigned with an immutable reference to </span><span style="color:#000000;">'''a'''</span><span style="color:#000000;">.</span>

<div style="color:#000000;">When you try to print them, there won't be any errors.</div>

<span style="color:#000000;">It </span>allows multiple<span style="color:#000000;"> immutable references to a piece of data simultaneously.</span>

<div style="color:#000000;">Save the program.</div>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| Run the code to see the output.

O<span style="color:#000000;">utput shows, variable </span>'''a'''<span style="color:#000000;"> can have </span>multiple <span style="color:#000000;">immutable references.</span>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <span style="color:#000000;">'''Slid</span>e 9<span style="color:#000000;">: Rules of borrowing:'''</span>

<div style="color:#000000;">2. Only 1 mutable reference to a data</div>
| style="color:#000000;" | The second rule states that you can have only one mutable reference to a data.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
| style="color:#252525;" |
|| <div style="color:#000000;">Let us see an example. </div>

<span style="color:#000000;">Clear the previous code. Copy paste the code from the </span>C<span style="color:#000000;">ode file.</span>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">fn main() {</div>

<div style="color:#000000;">let mut s = String::from("Hello ");</div>

<div style="color:#000000;">let r1 = &mut s;</div>

<div style="color:#000000;">let r2 = &mut s;</div>

<div style="color:#000000;">r1.push_str("World"); r2.push_str("Rust");</div>

<div style="color:#000000;">println!("{}",r1);</div>

<div style="color:#000000;">println!("{}",r2);</div>

<div style="color:#000000;">}</div>
|| <span style="color:#000000;">Here, the mutable variable </span><span style="color:#000000;">'''s'''</span><span style="color:#000000;"> is assigned to a string object </span><span style="color:#000000;">'''hello.'''</span>

<div style="color:#000000;">Variables r1, r2 are assigned with a mutable reference to s.</div>

<div style="color:#000000;">When both the references try to modify the data, rust wont allow this.</div>

<div style="color:#000000;">It will lead to a data race, where the data gets corrupted.</div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">fn main() {</div>

<div style="color:#000000;">let mut s = String::from("Hello ");</div>

<div style="color:#000000;">let r1 = &mut s;</div>

<span style="color:#000000;">'''//let r2 = &mut s;'''</span>

<div style="color:#000000;">r1.push_str("world"); </div>

<span style="color:#000000;">'''//r2.push_str("Rust");'''</span>

<div style="color:#000000;">println!("{}",r1);</div>

<div style="color:#000000;">'''//println!("{}",r2);'''</div>

<div style="color:#000000;">}</div>
|| <div style="color:#000000;">Run the code and check the error.</div>

<span style="color:#000000;">Let us </span>comment the code, related to the second<span style="color:#000000;"> mutable reference.</span>

<div style="color:#000000;">Save the program.</div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
| style="color:#000000;" |
|| Run the code to see the output.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">'''Slide 10:'''</div>

<div style="color:#000000;">'''Rules of Borrowing: The third Rule:'''</div>

|| <span style="color:#000000;">You </span><span style="color:#000000;">cannot mix</span><span style="color:#000000;">''' mutable '''</span><span style="color:#000000;">and</span><span style="color:#000000;">''' immutable references '''</span><span style="color:#000000;">to the same data at the same time.</span>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
| style="color:#000000;" |
|| <div style="color:#000000;">Let us understand through an example.</div>

<span style="color:#000000;">Copy and paste the code from the </span>'''C<span style="color:#000000;">ode file'''</span><span style="color:#000000;">.</span>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">fn main() {</div>

<div style="color:#000000;">let mut s = String::from("Hello ");</div>

<div style="color:#000000;">let r1 = &mut s;</div>

<span style="color:#000000;">'''//</span> <span style="color:#000000;">let r2 = &s;'''</span>

<div style="color:#000000;">r1.push_str("Rust");</div>

<div style="color:#000000;">println!("{}", r1);</div>

<div style="color:#000000;">}</div>
|| <span style="background-color:#ffffff;color:#000000;">Mutable variable</span><span style="background-color:#ffffff;color:#000000;">''' s '''</span><span style="background-color:#ffffff;color:#000000;">is assigned to a string object </span><span style="background-color:#ffffff;color:#000000;">'''hello'''</span><span style="background-color:#ffffff;color:#000000;">.</span>

<span style="background-color:#ffffff;color:#000000;">Here </span><span style="background-color:#ffffff;color:#000000;">'''r1 is '''</span><span style="background-color:#ffffff;color:#000000;">assigned </span><span style="background-color:#ffffff;">as </span><span style="background-color:#ffffff;color:#000000;">a mutable reference to s. </span>

<span style="background-color:#ffffff;">And</span><span style="background-color:#ffffff;">''' </span><span style="background-color:#ffffff;color:#000000;">r2'''</span><span style="background-color:#ffffff;color:#000000;"> </span><span style="background-color:#ffffff;">as</span><span style="background-color:#ffffff;color:#000000;"> </span><span style="background-color:#ffffff;">an immutable</span><span style="background-color:#ffffff;color:#000000;"> reference to </span><span style="background-color:#ffffff;color:#000000;">'''s'''</span><span style="background-color:#ffffff;color:#000000;">. </span>

One reference tries to modify the data while another reference tries to read data.

<div style="color:#000000;">It will lead to corrupt data because the reference didn’t get out of scope.</div>

<div style="color:#000000;">It still has the mutable reference and may change the data in the scope.</div>

<span style="color:#000000;">Comment the </span>line of <span style="background-color:#ffffff;color:#000000;">immutable reference to </span><span style="background-color:#ffffff;color:#000000;">'''s</span><span style="background-color:#ffffff;"> '''</span><span style="background-color:#ffffff;">as shown.</span>

<div style="color:#000000;">Save the program.</div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
| style="color:#000000;" |
|| <span style="color:#000000;">In the terminal, type </span><span style="color:#000000;">'''cargo run '''</span><span style="color:#000000;">and see the output.</span>

<div style="color:#000000;">Hence rust doesn't allow you to break all the above 3 rules.</div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
| style="color:#000000;" |
| style="color:#000000;" | Next we will see how dangling references occur and how Rust prevents them.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
| style="color:#000000;" |
|| <div style="color:#171717;">Let us understand with an example.</div>

<div style="color:#171717;">Copy and paste the code from the code file.</div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">fn get_reference() -> &String {</div>

<div style="color:#000000;">let s = String::from("Hello, Rust!");</div>

<div style="color:#000000;">&s // ❌ Error: `s` is dropped at the end of this function</div>

<div style="color:#000000;">} // `s` goes out of scope here, but we're trying to return a reference to it</div>

<div style="color:#000000;">fn main() {</div>

<div style="color:#000000;">let r = get_reference(); // Trying to use a reference to `s`, but `s` is already dropped</div>

<div style="color:#000000;">println!("{}", r);</div>

<div style="color:#000000;">}</div>
|| <span style="color:#000000;">Inside </span><span style="color:#000000;">'''get_reference(),'''</span><span style="color:#000000;"> we create a String named </span><span style="color:#000000;">'''s'''</span><span style="color:#000000;">.</span>

<span style="color:#000000;">In the next line, it returns </span>a<span style="color:#000000;"> reference to that string.</span>

<span style="color:#000000;">When the function ends, s goes </span><span style="color:#000000;">out of scope, </span><span style="color:#000000;">and its heap memory is freed.</span>

Here <span style="color:#000000;">we are trying to return a reference to t</span>his<span style="color:#000000;"> freed memory.</span>

<div style="color:#000000;">Hence, we will get an error.</div>

<span style="color:#000000;">When we try to run the main function, it </span>l<span style="color:#000000;">eads to an invalid memory.</span>(<span style="color:#000000;"> a </span><span style="color:#000000;">'''dangling reference'''</span><span style="color:#000000;">).</span>

<span style="color:#000000;">Save the program</span>.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
| style="color:#000000;" |
| style="color:#000000;" | Let us run the program and check the error.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">'''fn get_reference() -> String {'''</div>

<div style="color:#000000;">'''let s = String::from("Hello, Rust!");'''</div>

<div style="color:#000000;">'''s // ownership is moved out safely'''</div>

<div style="color:#000000;">'''} '''</div>
|| Let's see h<span style="color:#000000;">ow to correct this program?</span>

<span style="color:#000000;">Let us modify the program to return </span>a<span style="color:#000000;"> value not the reference.</span>

<span style="color:#000000;">Remove the</span><span style="color:#000000;">''' &'''</span><span style="color:#000000;"> from </span><span style="color:#000000;">'''s.'''</span>

<div style="color:#000000;">Save the program.</div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
| style="color:#000000;" |
| style="color:#000000;" | Now run the program and see the result.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
| style="color:#000000;" |
|| <div style="color:#000000;">This brings us to the end of this tutorial.</div>

<div style="color:#000000;">Let us summarize. </div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">'''Slide 8'''</div>

<div style="color:#000000;">'''Assignment'''</div>

<div style="color:#000000;">'''fn main() {'''</div>

<div style="color:#000000;">'''let fruit1 = String::from("Apple");'''</div>

<div style="color:#000000;">'''let fruit2 = fruit1; '''</div>

<div style="color:#000000;">'''println!("fruit1 = {}", fruit1); '''</div>

<div style="color:#000000;">'''println!("fruit2 = {}", fruit2);'''</div>

<div style="color:#000000;">'''}'''</div>
|| As an assignment,

Run the above code and fix the error.

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| <div style="color:#000000;">'''Slide 9 '''</div>

<div style="color:#000000;">'''Thank You'''</div>
|| Thank you for joining.
|-
|}
<div style="margin-left:-1.588cm;margin-right:-1.429cm;"></div>

@@ Line 8: / Line 8: @@
 || Welcome to the Spoken Tutorial on '''Borrowing in Rust.'''
 |-
-|| ''Slide 2'''
+|| '''Slide 2'''
-''Learning Objectives'''
+'''Learning Objectives'''
 || In this tutorial, we will learn about:
 * Borrowing and
@@ Line 16: / Line 16: @@
 |-
-|| ''Slide 3'''
+|| '''Slide 3'''
-''System Requirements'''
+'''System Requirements'''
 || To record this tutorial I’m using the follwoing setup
 |-
 || '''Slide 4'''
-''Code Files'''
+'''Code Files'''
 ||
 * The following code file is required to practise this tutorial.
@@ Line 29: / Line 29: @@
 |-
-|| ''Slide 5'''
+|| '''Slide 5'''
-''Borrowing'''
+'''Borrowing'''
 || Let us learn about borrowing.
@@ Line 39: / Line 39: @@
 |-
-|| ''Slide 6 '''
+|| '''Slide 6 '''
-''Borrowing - Example'''
+'''Borrowing - Example'''
 fn main() {
@@ Line 198: / Line 198: @@
 || Run the code to see the output.
 |-
-|| ''Slide 10'''
+|| '''Slide 10'''
-''Rules of Borrowing:  Rule 3'''
+'''Rules of Borrowing:  Rule 3'''
 || You cannot mix''' mutable '''and''' immutable references '''to the same data at the same time.
@@ Line 311: / Line 311: @@
 Let us summarize.
 |-
-|| ''Slide  12''
+|| '''Slide  12''
-''Assignment'''
+'''Assignment'''
 ''fn main() {'''
@@ Line 331: / Line 331: @@
 |-
-|| ''Slide 9 '''
+|| '''Slide 13 '''
 ''Thank You'''

@@ Line 333: / Line 333: @@
 || '''Slide 13 '''
-''Thank You'''
+'''Thank You'''
 || Thank you for joining.
 |-
 |}

@@ Line 18: / Line 18: @@
 <div style="color:#000000;">'''System Requirements'''</div>
-| style="color:#000000;" | To record this tutorial I’m using the follwoing setup
+| style="color:#000000;" | To record this tutorial I’m using the following setup
 |- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.101cm;padding-right:0.191cm;"
 || <span style="color:#000000;">'''Slide'''</span><span style="color:#000000;"> </span><span style="color:#000000;">'''5'''</span>

@@ Line 52: / Line 52: @@
 * <div style="margin-left:1.27cm;margin-right:0cm;">Here <span style="color:#000000;">‘</span><span style="color:#000000;">'''s’'''</span><span style="color:#000000;"> owns the string “</span><span style="color:#000000;">'''hello'''</span><span style="color:#000000;">”</span></div>
 * <div style="margin-left:1.27cm;margin-right:0cm;"><span style="color:#000000;">‘</span><span style="color:#000000;">'''s1'''</span><span style="color:#000000;">’ borrows ‘</span><span style="color:#000000;">'''s'''</span><span style="color:#000000;">’ by reference denoted by </span><span style="color:#000000;">'''&s'''</span><span style="color:#000000;">. </span></div>
 <span style="color:#000000;">But </span>ownership<span style="color:#000000;"> of the string is still with </span><span style="color:#000000;">'''s.'''</span>
 * <div style="margin-left:1.27cm;margin-right:0cm;"><span style="color:#000000;">'''s1 '''</span><span style="color:#000000;">is only allowed to read the data</span></div>