fnget_string_length(a:String)->usize{returna.len()}fnmain(){letv="hello".into();println!("length of hello is {}.",get_string_length(v));// 至此,`v`已经转移到函数内println!("{}",v);// 无法编译通过, error[E0382]: borrow of moved value: `v`} get_string_length本来只是想看...
packagecom.evswards.multihandle;importjava.util.ArrayList;importjava.util.List;publicclassTestJavaMulti001{publicstaticvoidmain(String[] args)throwsInterruptedException {classPoint{intx;inty;publicPoint(intx,inty){this.x = x;this.y = y; } }Pointp=newPoint(1,2); List<Thread> handles =newArrayL...
packagecom.evswards.multihandle;importjava.util.ArrayList;importjava.util.List;publicclassTestJavaMulti001{publicstaticvoidmain(String[]args)throws InterruptedException{classPoint{int x;int y;publicPoint(int x,int y){this.x=x;this.y=y;}}Point p=newPoint(1,2);List<Thread>handles=newArrayList<>...
fn main() { let s1 = String::from("hello"); let len = calculate_length(&s1); println!("The length of '{}' is {}.", s1, len); } fn calculate_length(s: &String) -> usize { s.len() } 针对此处更详细的内容,可以翻看我们之前的所有权 12. 结构体 struct,或者 structure,是一...
fn main(){lets=String::from("hello");letlen=calculate_length(&s);// 借用println!("The length of '{}' is {}.",s,len);}fn calculate_length(s:&String)->usize{s.len()} 结构体 (Structs) 结构体用于创建自定义类型,字段可以包含多种数据类型。
1. 类型引用 &T, &mut T原始指针 * const T, * mut T智能指针(拥有Drop, Deref特征)2. 引用&T 为 不可变引用, 是一种copy类型, 可以对变量T进行多次不可变引用;fn main() { let s1 = String::from(…
fn get_str<'a>(s: *const String) -> &'a str { unsafe { &*s } } fn main() { let soon_dropped = String::from("hello"); let dangling = get_str(&soon_dropped); drop(soon_dropped); println!("Invalid str: {}", dangling); // Invalid str: gӚ_` ...
letmutguess=String::new(); io::stdin().read_line(&mutguess).expect("无法读取行"); 所有权 所有权可以理解为命名空间+作用域+指针。 基本数据类型(值类型)变量在栈空间中可以复制。先给x赋值9(let x = 9),将x赋值给y等同于直接给y赋值9(let y = x 等同于let y = 9) ...
usestd::io;// preludefnmain() {println!("猜数!");println!("猜测一个数");// let mut foo = 1;// let bar = foo; // immutable// foo = 2;letmutguess= String::new(); io::stdin().read_line(&mutguess).expect("无法读取行");// io::Result Ok Errprintln!("你猜测的数是:{}...
let mut hello = String::from("Hello!"); //声明一个可变字符串变量 println!("{}",hello); //有判空、获得长度、获得占用空间、接续字符/字符串等类方法 println!("Length: {}",hello.len()); hello.push('!'); println!("{}",hello); ...