Rust in Action: Mastering Rust's Basic Data Types

ltaodream

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

<div class='showpostmsg'># 《Rust in Action》 Mastering Rust's Basic Data Types I reviewed the Rust basic data types in Chapter 2 and shared them with you. They are all here. You can learn them directly~ Let's get started with Rust! [TOC] # 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. ```go fn main() { let x: i32; // x is declared but not initialized, its value will be the zero value of type i32, that is, 0 println!("The value of x is: {}", x); // Output: The value of x is: 0 } ``` # Numeric type i: signed integer i8, i16, i32, i64 u: unsigned integer u8, u16, u32, u64 The number of bits in isize and usize depends on the number of bits in the specific CPU architecture. If the CPU is 64 bits, they are 64 bits. If the CPU is 32 bits, they are 32 bits. f: floating point numbers 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 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>

Jacktang

Strings need to be noted that String is not an array of char.

OK

ltaodream

Jacktang posted on 2024-4-26 07:24 Strings need to be noted that String is not an array of char,,, OK