Rust-Programming-Language/C2/Control-Flow/English - Revision history

Madhurig at 09:37, 12 August 2025

2025-08-12T09:37:00Z

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Nirmala Venkat: Created page with "{| border="1" |- || '''Visual Cue''' || '''Narration''' |- || '''Slide 1''' || Welcome to the Spoken Tutorial on
2025-08-11T09:04:28Z

Created page with "{| border="1" |- || '''Visual Cue''' || '''Narration''' |- || '''Slide 1''' || <span style="color:#000000;">Welcome to the Spoken Tutorial on </span><span style="color:#00000..."

New page
{| border="1"
|-
|| '''Visual Cue'''
|| '''Narration'''
|-

|| '''Slide 1'''
|| <span style="color:#000000;">Welcome to the Spoken Tutorial on </span><span style="color:#000000;">'''Control Flow '''</span><span style="color:#000000;">in </span><span style="color:#000000;">'''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
* Control Flow Statement </div>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.136cm;padding-right:0.191cm;"
|| <span style="color:#000000;">'''Slide </span>3'''

<div style="color:#000000;">'''System Requirements'''</div>
|| <span style="color:#000000;">This tutorial</span> is recorded<span style="color:#000000;"> using</span>
* <div style="color:#000000;">Ubuntu Linux OS version 22.04</div>
* <span style="color:#000000;">Rust 1.</span><span style="color:#000000;">80</span><span style="color:#000000;">.0 </span>
* <span style="color:#000000;">Visual </span>S<span style="color:#000000;">tudio </span>C<span style="color:#000000;">ode 1.19.0</span>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.136cm;padding-right:0.191cm;"
|| <span style="color:#000000;">'''Slide </span>4'''

<div style="color:#000000;">'''Prerequisites'''</div>
||
* <span style="color:#000000;">You should be familiar with compiling and running Rust files</span>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.136cm;padding-right:0.191cm;"
|| <span style="color:#000000;">'''Slide'''</span> '''5'''

<div style="color:#000000;">'''Code Files'''</div>
||
* <div style="color:#000000;">The following code file is required to practise this tutorial</div>
* <div style="color:#000000;">This file is provided in the code files link of this tutorial page</div>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.136cm;padding-right:0.191cm;"
| style="color:#000000;" |
|| W<span style="color:#000000;">e will see about conditional statements in Rust.</span>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.136cm;padding-right:0.191cm;"
|| <span style="color:#000000;">'''Slide</span> 6'''

<div style="color:#000000;">'''Conditional Statements'''</div>
|| <div style="color:#000000;">Rust supports </div>
* <div style="color:#000000;">if </div>
* <div style="color:#000000;">else if </div>
* <span style="color:#000000;">else</span><span style="color:#000000;">''' '''</span>

statements <span style="color:#000000;">for making decisions based on conditions.</span>

It <span style="color:#000000;">always returns a boolean value.</span>
|- 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;">Let us open the </span><span style="color:#000000;">'''visual code editor'''</span><span style="color:#000000;"> and</span><span style="color:#000000;"> understand the control </span><span style="color:#000000;">statements</span><span style="color:#000000;"> with examples.</span>
|- 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 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>

<div style="color:#000000;">We can see a terminal window at the bottom.</div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| > cd '''MyRustProject'''

'''>''' '''cargo new functions'''

|| Go to our working directory '''MyRustProject''' as explained earlier.

Type the command '''cargo new controlflow '''and press '''Enter'''

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

<div style="color:#000000;"></div>
|| <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, </span><span style="background-color:#ffffff;">copy and paste the code from the code 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 n = 100; </div>

<div style="color:#000000;">if n>100{ </div>

<div style="color:#000000;">println!("Greater than 100"); </div>

<div style="color:#000000;">}else if n==100{ </div>

<div style="color:#000000;">println!("Equal to 100"); </div>

<div style="color:#000000;">}else { </div>

<div style="color:#000000;">println!("Smaller than 100"); </div>

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

<div style="color:#000000;">} </div>
|| <span style="color:#000000;">Let us look at this example </span>for an''' if else'''<span style="color:#000000;"> statement.</span>

<span style="color:#000000;">If n is greater than 100, it </span>prints a<span style="color:#000000;"> </span>“greater than 100”<span style="color:#000000;"> statement. </span>

<div style="color:#000000;">If n equals 100, the second print statement will be executed. </div>

<span style="color:#000000;">If n is less than 100, it prints </span>“smaller than 100”<span style="color:#000000;">.</span>

<span style="color:#000000;">You can include multiple </span><span style="color:#000000;">'''else if'''</span><span style="color:#000000;"> statements </span><span style="background-color:#ffffff;color:#000000;">to check multiple conditions in sequence. </span>

<div style="color:#000000;">The condition must be true to run the code wrapped to it.</div>

<span style="color:#000000;">Press </span><span style="color:#000000;">'''ctrl and s '''</span><span style="color:#000000;">to save the file.</span>

Now let us run the program.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| In the menu bar, click on '''Terminal''' and select '''New Terminal.'''
|| <span style="color:#000000;">In the menu bar, click on </span>'''T<span style="color:#000000;">erminal'''</span><span style="color:#000000;"> and select </span><span style="color:#000000;">'''New Terminal.'''</span>

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

The output shows '''“equal to 100” '''as we assigned '''n '''as 100 in the program.
|- 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;">Next let us see </span><span style="color:#000000;">'''loop'''</span><span style="color:#000000;"> statements in Rust.</span>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| Slide

Loop
||
* <div style="margin-left:1.27cm;margin-right:0cm;">A loop is used to repeat a block of code until the specified condition is met</div>

* <div style="margin-left:1.27cm;margin-right:0cm;">The loop keyword creates an infinite loop unless you explicitly break out of it</div>

* <div style="margin-left:1.27cm;margin-right:0cm;">Rust provides several ways to loop, including '''loop''', '''while''', and '''for'''</div>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| Let us see an example for a '''loop''' program.

Clear the code window and replace the code from the code file as shown.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| fn main() {

let mut count = 0;
loop {
count += 1;
println!("Count: {}", count);
if count == 5 {
break;
}
}
}
|| This example has a mutable variable named '''count''' which is assigned to the value 0.

A loop is created in which it increases the '''count''' variable by 1.

It prints the value of count in the current iteration.

It will also check for the '''if '''statement condition.

When the variable '''count''' will be equal to 5, it will stop executing and come out of the loop.

If there is no if statement, it will execute infinitely.

Press '''ctrl and s '''to save the file.

Let us run the program.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| In the terminal, type '''cargo run'''

We can see the '''count''' variable is printed from 1 to 5.

It stops executing when the '''count''' reaches 5.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| Next we will see how the '''while''' loop works.

Replace the code from the codefile with the '''while''' loop program.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| fn main() {

let mut counter = 1;

// usage of while loop

while counter < 6 {

println!("{}", counter);

counter += 1;

}

}
|| The '''while''' loop runs as long as a condition is true.

Here, the loop keeps running till the '''counter''' variable is less than 6.

Inside the loop, we are increasing the value of the '''counter''' by 1.

After the 5th iteration, the value of the '''counter''' will be 6.

So the condition, '''counter''' '''< 6 '''becomes false and the loop is terminated.

Save the program.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| In the terminal, type '''cargo run'''

Check the output.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| <span style="background-color:#ffffff;">Next we will see about </span><span style="background-color:#ffffff;">'''For'''</span><span style="background-color:#ffffff;"> loop.</span>

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| '''Slide 7'''

'''For loop'''
||
* The '''for''' loop iterates over a range or a collection
* An '''iterator '''which provides a way to access elements one at a time.
* In a '''For''' loop, many collections like arrays, vectors, and ranges, implement the '''Iterator'''

|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| '''Slide 8'''

'''For loop -example'''
'''fn''' main() {
'''for''' n '''in''' 0..11 {
println!("{}", n);

}

}

|| The''' For''' loop has a definite start and endpoint with increment for each iteration.

A range with two dots like 0..11 is inclusive on the left.

i.e it starts at 0 and exclusive on the right. i.e ends at 10

This program will print numbers from 0 to 10.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| Next let us see an example of a for loop with an iterator method.

Clear the code window and copy and paste the code from the code file.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| fn main() {

let data = [2, 1, 17, 99, 34, 56];

for i in data.iter(){

println!("{}", i);

}

}
|| In this code, we have an array '''‘data’''' containing five integers.

The '''data.iter() '''method creates an iterator for the array '''data'''.

The '''for''' loop takes each element produced by the iterator and binds it to the variable '''data'''.

Inside the for loop, '''println''' is used to print the value of each element.

Save the file.

Let us execute the program.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| In the terminal, type '''cargo run'''

We can see the array elements are printed in sequence.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| We will learn some more concepts that work with a '''for''' loop.

Let us see how to use a '''reverse''' method in the for loop.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| '''fn''' main() {

for i in (1..=11).rev() {

println!("{i}...");

}
println!("Launch!");

}
|| Copy and paste the code from the code file.

<span style="color:#000000;">If we want the range to include 11 as well, we can write it as </span><span style="color:#000000;">'''(1..</span><nowiki>=11).</nowiki>'''

This is known as an inclusive range.

The '''rev() '''method is applied to the range to produce a reverse iterator.

This means the numbers will be fetched in reverse order.

Save the file.

Let us check the output.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
||
|| In the terminal, type '''cargo run'''

We can see the output displayed in the reverse order as expected.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| '''Slide 11'''

|| This brings us to the end of this tutorial.

Let us summarize.
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| '''Slide 12'''

'''Assignment'''
|| As an Assignment, do the following:

Write a program to print odd numbers between 11 and 1 using a for loop
*Hint: use Rev() method</div>
|- style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"
|| '''Slide 18'''
| style="color:#000000;" | Thank you for joining.
|-
|}
<div style="margin-left:-1.588cm;margin-right:-1.429cm;"></div>