Rust Function: Calculate Sum of Borrowed integers

Rust Ownership, Borrowing, and Lifetimes: Exercise-6 with Solution

Write a Rust function that borrows a slice of integers and calculates their sum.

Sample Solution:

Rust Code:

// Define a function named 'calculate_sum' that borrows a slice of integers and returns their sum
fn calculate_sum(numbers: &[i32]) -> i32 {
    // Initialize a variable 'sum' to store the sum of numbers
    let mut sum = 0;

    // Iterate over each element of the slice and add it to 'sum'
    for &num in numbers {
        sum += num;
    }

    sum // Return the sum
}

fn main() {
    let numbers = [1, 2, 3, 4, 5]; // Define an array of integers

    // Call the 'calculate_sum' function and pass a reference to 'numbers' to borrow it
    let sum = calculate_sum(&numbers);

    // Print the sum of all numbers in the slice
    println!("Sum of numbers: {}", sum);
}

Output:

Sum of numbers: 15

Explanation:

Here is a brief explanation of the above Rust code:

• fn calculate_sum(numbers: &[i32]) -> i32 { ... }: This is a function named calculate_sum that borrows a slice of integers (&[i32]) and returns their sum as an integer (i32). The parameter numbers is of type &[i32], indicating borrowing.
• Inside the function:
• We initialize a variable 'sum' to store the sum of numbers.
• We iterate over each element 'num' of the slice using a "for" loop, adding each element to 'sum'.
• We return the value of 'sum'.
• In the main function,
• Define an array of named 'numbers' containing some integers.
• Call the calculate_sum function and pass a reference to the array (&numbers) to borrow it.
• Finally, we print the sum of all numbers in the array slice returned by the function.

Rust Code Editor:

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