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  • rust笔记之变量和类型

    rust变量和类型

    变量声明

    可变变量mut

    类型推导

    类型别名type xx=xx

    静态变量


    常量

    基本类型: bool,char,整型,整型溢出,浮点类型,指针类型

    类型转换

    复合类型

    1. tuple
    2. struct, tuple struct
    3. enum例如Option<T>

    fn main() {
        println!("Hello, world!");
    
        let var1 :i32 = 123;
        println!("{}", var1);
    
        let mut x = 123;
        x = x+1;
        println!("{}", x);
    
        let x2 = 1234;
        println!("{}", x2);
    
        /*
        type age = i32;
        let x3 age = 12345;
        println!("{}", x3);
        */
    
        static S1:i32 = 124321;
        println!("{}", S1);
    
        const ABC:i32 = 123;
        println!("{}", ABC);
    
        let flag :bool = true;
        println!("{}", flag);
    
        let var4 = 0x_123_ABC;
        println!("{}", var4);
    
        let tup1 = (1i32, 2i32);
        println!("{}", tup1.0);
        let tup2 = (1,2);
        println!("{}", tup2.0);
    
        //let emmpty:() = ();
        //println!("{}", empty);
    
        struct Point{
            x:i32,
            y:i32,
        }
    
        let p1 = Point{x:0, y:1};
        println!("{},{}", p1.x, p1.y);
    
        struct Color(i32,i32, i32);
        let c = Color{0:1,1:2,2:3};
        println!("{}", c.0);
    
        let n:Name = Name::Int(20);
        read_num(&n);
    
        let n2:Name = Name::Float(20.123);
        read_num(&n2);
    
    
    }
    
    #[derive(Debug)]
    enum Name {
        Int(i32),
        Float(f32),
    }
    
    fn read_num(num :&Name){
        match num{
            &Name::Int(value) => println!("int {}", value),
            &Name::Float(value) => println!("float {}", value),
        }
    }
    

      

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  • 原文地址:https://www.cnblogs.com/beckbi/p/14618258.html
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