How to print a Vec?

Question

I tried the following code:

fn main() {
    let v2 = vec![1; 10];
    println!(\"{}\", v2);
}

But the compiler complains:

Answer 1

Here is a one-liner which should also work for you:

println!("[{}]", v2.iter().fold(String::new(), |acc, &num| acc + &num.to_string() + ", "));

Here is a runnable example.

---

In my own case, I was receiving a Vec<&str> from a function call. I did not want to change the function signature to a custom type (for which I could implement the Display trait).

For my one-of case, I was able to turn the display of my Vec into a one-liner which I used with println!() directly as follows:

println!("{}", myStrVec.iter().fold(String::new(), |acc, &arg| acc + arg));

(The lambda can be adapted for use with different data types, or for more concise Display trait implementations.)