rustlings/exercises/collections/vec2.rs

39 lines
852 B
Rust
Raw Permalink Normal View History

2020-10-26 13:54:32 +07:00
// vec2.rs
// A Vec of even numbers is given. Your task is to complete the loop
// so that each number in the Vec is multiplied by 2.
//
// Make me pass the test!
//
// Execute the command `rustlings hint collections2` if you need
// hints.
// I AM NOT DONE
fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
for i in v.iter_mut() {
// TODO: Fill this up so that each element in the Vec `v` is
// multiplied by 2.
}
// At this point, `v` should be equal to [4, 8, 12, 16, 20].
v
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_vec_loop() {
let v: Vec<i32> = (1..).filter(|x| x % 2 == 0).take(5).collect();
let ans = vec_loop(v.clone());
assert_eq!(
ans,
v.iter()
.map(|x| x * 2)
.collect::<Vec<i32>>()
);
}
}