hanksjctsai / rust_practice

my practice for learning rust

rust_practice

my practice for learning rust

Day01 Notes

Install rust & visual studio code's extensions

Install Rust:

• Rust-lang

Visual studio code extensions

• rust-analyzer
• Error Lens
• Even Better TOML

About rust common commands

1. rustup
2. rustc

About rust's package management tool

1. cargo

Day02 Notes

Ch02_01 Variables

Declare immutable varianle

• Let x: i32 = 5; or let x = 5; x is i32

Declare mutable varianle

• Let mut x: i32 = 5; or let mut x = 5; x is i32

Shadowing

Shadowing

fn variables_shadowing() {
    let x = 5;
    let x = x + 1;
    let x = x * 2;
    println!("The value of x is: {}", x);
    // The value of x is: 12
}

Non-Shadowing

fn variables_shadowing() {
    let x = 5;
    let y = x + 1;
    let z = y * 2;
    println!("The value of z is: {}", z);
    // The value of z is: 12
}

shadowing vs mutable

1. The shadowing can change datatype, but mutable can't. 2. The shadowing is alway immutable.

Naming rule for variable

1. Snake Case: Let _nice_count : i32 = 0;
2. Pascal Case(For enumerate and structure)

Casting a value to a different type

Let __nice_count_one : i32 = 0;
Let _nice_count_two = __nice_count_one as i32;

Print out variable

println!("Value is: {}", __nice_count_one); println!("Value is: {__nice_count_one}");