How to create an Empty Vector in Rust


How to create an Empty Vector in Rust ?

Answer

To create an empty vector in Rust, you can use the Vec::new method or the vec![] macro.



✐ Examples

1 Create an Empty Vector Using Vec::new

In this example,

  1. We use the Vec::new method to create an empty vector.
  2. The Vec::new method returns a new vector that is empty and does not allocate memory until elements are added to it.
  3. We assign the result to a variable named empty_vector using the let keyword.
  4. Finally, we print the empty_vector using the println! macro to verify that it is indeed empty.

Rust Program

fn main() {
    let empty_vector: Vec<i32> = Vec::new();
    println!("Empty vector: {:?}", empty_vector);
}

Output

Empty vector: []

2 Create an Empty Vector Using vec![] Macro

In this example,

  1. We use the vec![] macro to create an empty vector.
  2. The vec![] macro creates a new vector that is empty and can hold any type of elements specified in the assignment.
  3. We assign the result to a variable named empty_vector using the let keyword.
  4. Finally, we print the empty_vector using the println! macro to verify that it is indeed empty.

Rust Program

fn main() {
    let empty_vector: Vec<i32> = vec![];
    println!("Empty vector: {:?}", empty_vector);
}

Output

Empty vector: []

Summary

In this tutorial, we learned How to create an Empty Vector in Rust language with well detailed examples.




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