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This commit is contained in:
horaoen 2023-12-29 14:11:32 +08:00
parent 0cbbe09cc6
commit bbf9d15391
3 changed files with 14 additions and 17 deletions
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13
exercises/12_options/options1.rs
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@ -3,8 +3,6 @@
// Execute `rustlings hint options1` or use the `hint` watch subcommand for a // Execute `rustlings hint options1` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
// This function returns how much icecream there is left in the fridge. // This function returns how much icecream there is left in the fridge.
// If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them // If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
// all, so there'll be no more left :( // all, so there'll be no more left :(
@ -12,8 +10,13 @@ fn maybe_icecream(time_of_day: u16) -> Option<u16> {
// We use the 24-hour system here, so 10PM is a value of 22 and 12AM is a // We use the 24-hour system here, so 10PM is a value of 22 and 12AM is a
// value of 0 The Option output should gracefully handle cases where // value of 0 The Option output should gracefully handle cases where
// time_of_day > 23. // time_of_day > 23.
// TODO: Complete the function body - remember to return an Option! if time_of_day > 0 && time_of_day <= 10 {
??? Some(5)
} else if time_of_day <= 24 {
Some(0)
} else {
None
}
} }
#[cfg(test)] #[cfg(test)]
@ -34,6 +37,6 @@ mod tests {
// TODO: Fix this test. How do you get at the value contained in the // TODO: Fix this test. How do you get at the value contained in the
// Option? // Option?
let icecreams = maybe_icecream(12); let icecreams = maybe_icecream(12);
assert_eq!(icecreams, 5); assert_eq!(icecreams.unwrap(), 0);
} }
} }

14
exercises/12_options/options2.rs
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@ -3,17 +3,13 @@
// Execute `rustlings hint options2` or use the `hint` watch subcommand for a // Execute `rustlings hint options2` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
#[cfg(test)]
mod tests { mod tests {
#[test] #[test]
fn simple_option() { fn simple_option() {
let target = "rustlings"; let target = "rustlings";
let optional_target = Some(target); let optional_target = Some(target);
// TODO: Make this an if let statement whose value is "Some" type if let Some(word) = optional_target {
word = optional_target {
assert_eq!(word, target); assert_eq!(word, target);
} }
} }
@ -29,12 +25,12 @@ mod tests {
let mut cursor = range; let mut cursor = range;
// TODO: make this a while let statement - remember that vector.pop also while let Some(Some(integer)) = optional_integers.pop() {
// adds another layer of Option<T>. You can stack `Option<T>`s into
// while let and if let.
integer = optional_integers.pop() {
assert_eq!(integer, cursor); assert_eq!(integer, cursor);
cursor -= 1; cursor -= 1;
if cursor == 0 {
break;
}
} }
assert_eq!(cursor, 0); assert_eq!(cursor, 0);

4
exercises/12_options/options3.rs
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@ -3,8 +3,6 @@
// Execute `rustlings hint options3` or use the `hint` watch subcommand for a // Execute `rustlings hint options3` or use the `hint` watch subcommand for a
// hint. // hint.
// I AM NOT DONE
struct Point { struct Point {
x: i32, x: i32,
y: i32, y: i32,
@ -14,7 +12,7 @@ fn main() {
let y: Option<Point> = Some(Point { x: 100, y: 200 }); let y: Option<Point> = Some(Point { x: 100, y: 200 });
match y { match y {
Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y), Some(ref p) => println!("Co-ordinates are {},{} ", p.x, p.y),
_ => panic!("no match!"), _ => panic!("no match!"),
} }
y; // Fix without deleting this line. y; // Fix without deleting this line.