From 17f5f39e513c3d6a0ccfdf1f22c65a5cb46ac485 Mon Sep 17 00:00:00 2001 From: jiangker Date: Mon, 8 Jul 2024 15:12:23 +0800 Subject: [PATCH] study 4-6 --- exercises/04_primitive_types/primitive_types1.rs | 1 + exercises/04_primitive_types/primitive_types2.rs | 2 +- exercises/04_primitive_types/primitive_types3.rs | 2 +- exercises/04_primitive_types/primitive_types4.rs | 2 +- exercises/04_primitive_types/primitive_types5.rs | 2 +- exercises/04_primitive_types/primitive_types6.rs | 2 +- exercises/05_vecs/vecs1.rs | 2 +- exercises/05_vecs/vecs2.rs | 3 ++- exercises/06_move_semantics/move_semantics1.rs | 2 +- exercises/06_move_semantics/move_semantics2.rs | 2 +- exercises/06_move_semantics/move_semantics3.rs | 2 +- exercises/06_move_semantics/move_semantics4.rs | 2 +- exercises/06_move_semantics/move_semantics5.rs | 8 ++++---- exercises/quizzes/quiz1.rs | 2 +- 14 files changed, 18 insertions(+), 16 deletions(-) diff --git a/exercises/04_primitive_types/primitive_types1.rs b/exercises/04_primitive_types/primitive_types1.rs index 84923c75..1a228b6d 100644 --- a/exercises/04_primitive_types/primitive_types1.rs +++ b/exercises/04_primitive_types/primitive_types1.rs @@ -9,6 +9,7 @@ fn main() { // TODO: Define a boolean variable with the name `is_evening` before the `if` statement below. // The value of the variable should be the negation (opposite) of `is_morning`. // let … + let is_evening: bool = false; if is_evening { println!("Good evening!"); } diff --git a/exercises/04_primitive_types/primitive_types2.rs b/exercises/04_primitive_types/primitive_types2.rs index 14018475..6efa981b 100644 --- a/exercises/04_primitive_types/primitive_types2.rs +++ b/exercises/04_primitive_types/primitive_types2.rs @@ -16,7 +16,7 @@ fn main() { // below with your favorite character. // Try a letter, try a digit (in single quotes), try a special character, try a character // from a different language than your own, try an emoji 😉 - // let your_character = ''; + let your_character = '1'; if your_character.is_alphabetic() { println!("Alphabetical!"); diff --git a/exercises/04_primitive_types/primitive_types3.rs b/exercises/04_primitive_types/primitive_types3.rs index 9b79c0cf..a2af98fb 100644 --- a/exercises/04_primitive_types/primitive_types3.rs +++ b/exercises/04_primitive_types/primitive_types3.rs @@ -1,6 +1,6 @@ fn main() { // TODO: Create an array called `a` with at least 100 elements in it. - // let a = ??? + let a = "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890"; if a.len() >= 100 { println!("Wow, that's a big array!"); diff --git a/exercises/04_primitive_types/primitive_types4.rs b/exercises/04_primitive_types/primitive_types4.rs index 16e4fd93..a15feb1c 100644 --- a/exercises/04_primitive_types/primitive_types4.rs +++ b/exercises/04_primitive_types/primitive_types4.rs @@ -9,7 +9,7 @@ mod tests { let a = [1, 2, 3, 4, 5]; // TODO: Get a slice called `nice_slice` out of the array `a` so that the test passes. - // let nice_slice = ??? + let nice_slice = &a[1..4]; assert_eq!([2, 3, 4], nice_slice); } diff --git a/exercises/04_primitive_types/primitive_types5.rs b/exercises/04_primitive_types/primitive_types5.rs index 6e00ef51..bdacbd9f 100644 --- a/exercises/04_primitive_types/primitive_types5.rs +++ b/exercises/04_primitive_types/primitive_types5.rs @@ -2,7 +2,7 @@ fn main() { let cat = ("Furry McFurson", 3.5); // TODO: Destructure the `cat` tuple in one statement so that the println works. - // let /* your pattern here */ = cat; + let (name, age): (&str, f32) = cat; println!("{name} is {age} years old"); } diff --git a/exercises/04_primitive_types/primitive_types6.rs b/exercises/04_primitive_types/primitive_types6.rs index a97e5311..3ca216b0 100644 --- a/exercises/04_primitive_types/primitive_types6.rs +++ b/exercises/04_primitive_types/primitive_types6.rs @@ -10,7 +10,7 @@ mod tests { // TODO: Use a tuple index to access the second element of `numbers` // and assign it to a variable called `second`. - // let second = ???; + let second: i32 = numbers.1; assert_eq!(second, 2, "This is not the 2nd number in the tuple!"); } diff --git a/exercises/05_vecs/vecs1.rs b/exercises/05_vecs/vecs1.rs index 68e1affa..f88b702f 100644 --- a/exercises/05_vecs/vecs1.rs +++ b/exercises/05_vecs/vecs1.rs @@ -3,7 +3,7 @@ fn array_and_vec() -> ([i32; 4], Vec) { // TODO: Create a vector called `v` which contains the exact same elements as in the array `a`. // Use the vector macro. - // let v = ???; + let v = a.to_vec(); (a, v) } diff --git a/exercises/05_vecs/vecs2.rs b/exercises/05_vecs/vecs2.rs index a9be2580..bef006a9 100644 --- a/exercises/05_vecs/vecs2.rs +++ b/exercises/05_vecs/vecs2.rs @@ -4,6 +4,7 @@ fn vec_loop(input: &[i32]) -> Vec { for element in input { // TODO: Multiply each element in the `input` slice by 2 and push it to // the `output` vector. + output.push(element * 2) } output @@ -24,7 +25,7 @@ fn vec_map(input: &[i32]) -> Vec { input .iter() .map(|element| { - // ??? + element * 2 }) .collect() } diff --git a/exercises/06_move_semantics/move_semantics1.rs b/exercises/06_move_semantics/move_semantics1.rs index 4eb3d618..bf559432 100644 --- a/exercises/06_move_semantics/move_semantics1.rs +++ b/exercises/06_move_semantics/move_semantics1.rs @@ -1,6 +1,6 @@ // TODO: Fix the compiler error in this function. fn fill_vec(vec: Vec) -> Vec { - let vec = vec; + let mut vec = vec; vec.push(88); diff --git a/exercises/06_move_semantics/move_semantics2.rs b/exercises/06_move_semantics/move_semantics2.rs index a3ab7a0f..e205b813 100644 --- a/exercises/06_move_semantics/move_semantics2.rs +++ b/exercises/06_move_semantics/move_semantics2.rs @@ -20,7 +20,7 @@ mod tests { fn move_semantics2() { let vec0 = vec![22, 44, 66]; - let vec1 = fill_vec(vec0); + let vec1 = fill_vec(vec0.clone()); assert_eq!(vec0, [22, 44, 66]); assert_eq!(vec1, [22, 44, 66, 88]); diff --git a/exercises/06_move_semantics/move_semantics3.rs b/exercises/06_move_semantics/move_semantics3.rs index 11dbbbeb..4a90c211 100644 --- a/exercises/06_move_semantics/move_semantics3.rs +++ b/exercises/06_move_semantics/move_semantics3.rs @@ -1,5 +1,5 @@ // TODO: Fix the compiler error in the function without adding any new line. -fn fill_vec(vec: Vec) -> Vec { +fn fill_vec(mut vec: Vec) -> Vec { vec.push(88); vec diff --git a/exercises/06_move_semantics/move_semantics4.rs b/exercises/06_move_semantics/move_semantics4.rs index 83a03440..dda27271 100644 --- a/exercises/06_move_semantics/move_semantics4.rs +++ b/exercises/06_move_semantics/move_semantics4.rs @@ -10,8 +10,8 @@ mod tests { fn move_semantics4() { let mut x = 100; let y = &mut x; - let z = &mut x; *y += 100; + let z = &mut x; *z += 1000; assert_eq!(x, 1200); } diff --git a/exercises/06_move_semantics/move_semantics5.rs b/exercises/06_move_semantics/move_semantics5.rs index fc593387..d3e16868 100644 --- a/exercises/06_move_semantics/move_semantics5.rs +++ b/exercises/06_move_semantics/move_semantics5.rs @@ -6,18 +6,18 @@ fn main() { let data = "Rust is great!".to_string(); - get_char(data); + get_char(&data); - string_uppercase(&data); + string_uppercase(data); } // Shouldn't take ownership -fn get_char(data: String) -> char { +fn get_char(data: &String) -> char { data.chars().last().unwrap() } // Should take ownership -fn string_uppercase(mut data: &String) { +fn string_uppercase(mut data: String) { data = data.to_uppercase(); println!("{data}"); diff --git a/exercises/quizzes/quiz1.rs b/exercises/quizzes/quiz1.rs index 04fb2aaf..e9ac9a94 100644 --- a/exercises/quizzes/quiz1.rs +++ b/exercises/quizzes/quiz1.rs @@ -10,7 +10,7 @@ // TODO: Write a function that calculates the price of an order of apples given // the quantity bought. -// fn calculate_price_of_apples(???) -> ??? { ??? } +fn calculate_price_of_apples(num: i32) -> i32 { if num <= 40 { num * 2 } else { num } } fn main() { // You can optionally experiment here.