study_rust_example/common_collection/
string_study.rs

1fn combine_str() {
2    let s1 = String::from("spring.");
3    let s2 = String::from("summer.");
4    let s3 = String::from("winter.");
5    let s4 = String::from("autumn.");
6    let s5 = s1 + &s2;
7    let s6 = s2 + "-" + &s3 + "_" + &s4;
8    println!("s5 {s5} s6 {s6}");
9    let s1 = String::from("spring.");
10    let s2 = String::from("summer.");
11    let s3 = String::from("winter.");
12    let s7 = format!("{s1}-{s2}_{s3}");
13    println!("s7 {s7}");
14}
15
16fn slice_str() {
17    // 2byte
18    let str_val = "Здравствуйте";
19    let s = &str_val[0..4];
20    println!("s: {s}");
21}
22
23fn iterator_str() {
24    let str_val = "Здравствуйте";
25    println!("iterator_str :");
26    for c in str_val.chars() {
27        print!("{c} ");
28    }
29    println!();
30    for c in str_val.bytes() {
31        print!("{c} ");
32    }
33}
34
35pub fn string_usage_study() {
36    let mut str_val = String::new();
37    // s1 和 s2之间的操作等效；
38    let s1 = "hello string".to_string();
39    let s2 = String::from("[String::from] hello.");
40    str_val.push_str("push str hello rust.");
41    str_val.push('&');
42    println!("str_val {}, s1 {}, s2 {}", str_val, s1, s2);
43    let s3 = s1 + &s2;
44    println!("s3: {s3}");
45    combine_str();
46    slice_str();
47    iterator_str();
48}