Rust in Action: Mastering Rust's Basic Data Types

ltaodream

Rust in Action: Mastering Rust's Basic Data Types [Copy link]

<div class='showpostmsg'><i class="pstatus"> This post was last edited by ltaodream on 2024-4-25 12:39 </i> # 《Rust in Action》 Mastering Rust's Basic Data Types I reviewed the Rust basic data types in Chapter 2 and shared them with everyone. They are all here. You can learn them directly~ Let's get started with Rust! # Assignment ```go fn main() { let a: u32 = 10; } ``` Like Go, Rust must be initialized before the first use. Local variables need to be explicitly initialized, while global variables and static variables in Rust will receive automatic zero-value initialization. But starting from version 1.38, explicit initialization is required to enhance security and reduce undefined behavior.```go fn main() { let x: i32 = 5; println!("The value of x is: {}", x); // Output: The value of x is: 5 } ``` # Numeric type i: signed integer i8, i16, i32, i64 u: unsigned integer u8, u16, u32, u64 The number of bits of isize and usize is related to the number of bits of the specific CPU architecture. If the CPU is 64 bits, they are 64 bits, and if the CPU is 32 bits, they are 32 bits. f: floating point number f32, f64 **Rust's type safety ensures that data of different types cannot be compared** # Boolean type bool ```go let t = true; let f: bool = false; ``` # Character type char ```go fn main() { let a = 'a'; let b: char = 'B'； } ``` # String Note!! **String is not an array of char!! ** String stores the UTF8 encoding of Unicode strings at the bottom layer, while char stores Unicode Scalar Value directly. ```go fn main() { let hello = String::from("hello eeworld!"); } ``` # Byte string network programming is mostly used```go fn main() { let bytestring: &[u8; 13] = b"hello eeworld"; } ``` # Array fixed length```go fn main() { let a: [i32; 2] = [1, 2]; let a = [1, 2]; } ``` # Dynamic array Vector ```go fn main() { let mut v = vec![1, 2, 3]; // The mut keyword allows modification of v and its elements v.push(4); // Add a new element to v v[1] = 20; // Modify the element at the second position in v println!("{:?}", v); // Output: [1, 20, 3, 4] } ``` # Hash table```go fn main() { use std::collections::HashMap; let mut a = HashMap::new(); a.insert(String::from("eeworld"), 10); a.insert(String::from("rust"), 20); } ```</div><script> var loginstr = '<div class="locked">To view all the contents of the post, please <a href="/bbs/member.php?mod=logging&action=login" style="color:#e60000" class="loginf">log in</a> or <a href="/bbs/member.php?mod=register_eeworld.php&action=wechat" style="color:#e60000" target="_blank">register</a></div>'; if(parseInt(discuz_uid)==0){ } </script><script type="text/javascript">(function(d,c){var a=d.createElement("script"),m=d.getElementsByTagName("script")[0],eewurl="//counter.eeworld.com.cn/pv/count/";a.src=eewurl+c;m.parentNode.insertBefore(a,m)})(document,523)</script>

ltaodream

Come on, let's review and study together! I should post the right module this time

hellokitty_bean

Host:

fn main() {
let x: i32; // x is declared but not initialized, its value will be the zero value of type i32, i.e. 0
println!("The value of x is: {}", x); // Output: The value of x is: 0
}
Is there a requirement to declare global or static variables? Why does this code give me an error on RR? Initialization is required

ltaodream

hellokitty_bean posted on 2024-4-25 09:14 Original poster: fn main() { let x: i32; // x is declared but not initialized, its value will be the zero value of type i32, that is, 0 ...

The old version is like this, the new version is about to be announced, I will change the description

ltaodream

hellokitty_bean posted on 2024-4-25 09:14 Original poster: fn main() { let x: i32; // x is declared but not initialized, its value will be the zero value of type i32, that is, 0 ...

Starting from version 1.38, explicit initialization is required to enhance security and reduce undefined behavior

hellokitty_bean

hellokitty_bean posted on 2024-4-25 09:14 Original poster: fn main() { let x: i32; // x is declared but not initialized, its value will be the zero value of type i32, that is, 0 ...

Hmm, thank you for the review and detailed description!

Like the OP!

Learn together and make progress together

lugl4313820

This is indeed a good summary, I have learned a lot, thanks for sharing!