Modify vector elements with Rust Closure function

Rust Closures and Higher-Order Functions: Exercise-3 with Solution

Write a Rust function that iterates over a vector of integers and applies a closure to each element, modifying the original vector.

Sample Solution:

Rust Code:

fn apply_closure_to_vector<F>(vector: &mut Vec<i32>, mut closure: F)
where
    F: FnMut(&mut i32), // Define the closure trait bound
{
    for num in vector.iter_mut() { // Iterate over each element in the vector
        closure(num); // Apply the closure to the current element
    }
}

fn main() {
    let mut numbers = vec![100, 200, 300, 400, 500]; // Define a vector of integers
    println!("Original vector: {:?}", numbers); // Print the original vector
    
    // Define a mutable closure that adds one to each element
    let mut add_one = |x: &mut i32| *x += 1;
    
    // Apply the closure to each element of the vector
    apply_closure_to_vector(&mut numbers, &mut add_one);
    
    // Print the modified vector
    println!("Modified vector: {:?}", numbers);
}

Output:

Original vector: [100, 200, 300, 400, 500]
Modified vector: [101, 201, 301, 401, 501]

Explanation:

In the exercise above,

• The "apply_closure_to_vector()" function:
• This function takes two parameters: a mutable reference to a vector of integers (vector: &mut Vec<i32>) and a mutable closure (closure: F) where 'F' is a generic type that represents any closure that takes a mutable reference to an 'i32'.
• Inside the function, it iterates over each element of the vector using "iter_mut()", which allows mutable access to each element.
• For each element, it applies the closure "closure" by invoking it with the current element as an argument (closure(num)).
• The main function:
• It initializes a vector of integers "numbers" with values [100, 200, 300, 400, 500].
• It defines a closure "add_one" using the |parameter| { body } syntax. This closure takes a mutable reference to an 'i32' and increments the value by 1 (*x += 1).
• It calls the "apply_closure_to_vector()" function with a mutable reference to 'numbers' and the closure "add_one".
• After applying the closure to each element of the vector, it prints the modified vector.

Rust Code Editor:

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