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Mutable empty vector for numbers (push)

  • push

  • mut

  • vec!

  • We can also create a mutable empty vector without even declaring the types of the values.

  • When we push the first value that's how Rust will know what is the type of the elements of the vector.

  • Trying to push values of other types would then generate a compilation error.

fn main() {
    let mut names = vec![];
    println!("{:?}", names);

    names.push(23);

    // names.push("hello"); // error[E0308]: mismatched types - expected integer, found `&str`
    // names.push(3.14);    // error[E0308]: mismatched types - expected integer, found floating-point number
    names.push(19);

    println!("{:?}", names);
    for name in names {
        println!("{}", name);
    }
}
[]
[23, 19]
23
19