Quiz

Question 1

True or false:

iter() is a method implemented for hash maps that returns all key-value pairs in the order they were added.

Question 2

Fill in the blank, using a method you learned in this chapter, to shorten the vector below by five elements.

fn main() {
 let mut v = vec![5.12; 20];
 v.;
 println!("{}", v.len())
}

Question 3

What is the printed output of the following?

fn main() {
 let mut a = vec![49, 57, 12];
 let mut b = Vec::from([43, 21, 56, 105]); // converting array into vec
 a.append(&mut b);
 a.reverse();
 println!("{}", a.remove(0))
}

Question 4

Fill in both blanks below so that the hash map has 32-bit unsigned integer keys and single character values.

use std::collections::HashMap;

fn main() {
 let map: HashMap< , > = HashMap::new();
 println!("{:?}", map)
}

Question 5

In light of your knowledge of how iter() behaves on hash maps, how does it behave for vectors?