它们是使用构造函数HashMap::new创建的: // hashmaps.rs use std::collections::HashMap; fn main() { let mut fruits = HashMap::new(); fruits.insert("apple", 3); fruits.insert("mango", 6); fruits.insert("orange", 2); fruits.insert("avocado", 7); for (k, v) in &fruits { pri...
match_single_variant(Fruit::Orange); // Output: It's not an apple! } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 在上述例子中,我们定义了一个名为Fruit的枚举类型,有三个成员:Apple、Orange和Banana。match_single_variant函数使用match表达式匹配输入的fruit枚举值...
enumFruit{Apple,Orange,Banana,}fnmatch_single_variant(fruit:Fruit){match fruit{Fruit::Apple=>println!("It's an apple!"),_=>println!("It's not an apple!"),}}fnmain(){match_single_variant(Fruit::Apple);// Output: It's an apple!match_single_variant(Fruit::Orange);// Output: It's...
}else{println!("Using orange as the background color"); } }else{println!("Using blue as the background color"); } } While let 条件循环 只要模式继续满足匹配的条件,那它允许 while 循环一直运行 fnmain() {letmutstack= Vec::new(); stack.push(1); stack.push(2); stack.push(3);whilel...
println!("Using orange as the background color"); } } else { println!("Using blue as the background color!"); } } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 与match表达式不同,if let表达式的不利之处在于...
");}elseifletOk(age) = age {//像 match 分支那样引入覆盖变量ifage >30{//条件需要位于这个代码块内部println!("Using purple as the background color");}else{println!("Using orange as the background color");}}else{println!("Using blue as the background color");}//打印出 Using purple ...
("Using your favorite color, {color}, as the background");}elseifis_tuesday{println!("Tuesday is green day!");}elseifletOk(age)=age{ifage>30{println!("Using purple as the background color");}else{println!("Using orange as the background color");}}else{println!("Using blue as ...
//g++ pngdetail.cpp lodepng_util.cpp lodepng.cpp -ansi -pedantic -Wall -Wextra -o pngdetail -O3 /* Utility program that shows a lot of information in the console about a PNG file, including color type, text chunks, the names and sizes of all chunks in the image, all the zlib compre...
/// an associated RGB color space into a luma value and /// two chroma values called chrominance green and chrominance orange. YCgCo = 8, /// - Rec. ITU-R BT.2020-2 (non-constant luminance) /// - Rec. ITU-R BT.2100-2 Y′CbCr BT2020NonConstantLuminance = 9, /// Rec. ITU-...
}else{println!("Using orange as the background color"); } }else{println!("Using blue as the background color"); } } // while letletmutstack= Vec::new(); stack.push(1); stack.push(2); stack.push(3);whileletSome(top) = stack.pop() {println!("{}", top); ...