Guidance related to code

help
1

i am very new to rust programming and i am writing a code in which i have 3 files under src folder i.e main.rs, mod_a.rs and mod_b.rs and i want to access mob_b.rs in mod_a.rs i have already written mod mod_b in main.rs and use crate::mod_b::function2; (function2 is defined in my mod_b.rs) in mod_a.rs but i wont compile it will giver error. i am attaching the pictures of code below please have alook in it i am very confuse. thanks in advance for your time and consideration.

2

main.rs
image

3

mod_a.rs:
image

4

mod_b.rs:
image

5

the error message is shown below:

image
image711×287 13.3 KB

please help me to resolve the issue.

6

function1 doesn't return anything, so you cannot assign the result of it back into input_data. It would work if function1 looked like this:

pub fn function1(data1: f32) -> f32 {
    function2(data1 * 9.0)
}

The differences are:

  • A return type has been added to the function signature (-> f32).
  • The semi-colon (;) has been removed from the function body (using a semi-colon throws the value away and returns nothing.

(Also, in future, please provide your code/error messages as text rather than as images - it makes it easier for people to copy and paste your code so they can help fix it!)

2 Likes
7

thanks for your kind response brother can u plz help i want to store value from function2 in mod_b.rs in input_data how to write the code for this .

8

Are you asking how to call function2 from main? If so:

mod mod_a;
mod mod_b;

fn main() {
    let mut input_data: f32 = 46.5;

    input_data = mod_b::function2(input_data);
    println!("{}", input_data);
}

If you still want to call function2 via function1, make the change I showed you in my previous reply instead.

9

And when you do this, please follow the formatting guide for your code

https://users.rust-lang.org/t/forum-code-formatting-and-syntax-highlighting/42214/7

5 Likes
10

thanks for your reply but i want to call function2 from function1 and the vaue return from function2 i want to store that value in input_data variable in main.

11

Then you need to return the output of function2 from function1, as shown in my first reply. You can't return the value directly from function2 to main without passing it up the stack via function1.

12

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