X-Git-Url: https://piware.de/gitweb/?p=learn-rust.git;a=blobdiff_plain;f=src%2Fmain.rs;h=ff65a0611a6e7b40a0a86501a239ab657cc4156a;hp=058f8584cf31063cdef5dc9cd61a9daf38bfce00;hb=a8b3fed27dcb4a76333ac93aaa5f4143fe854ef8;hpb=824fd4371bafc487163edf33cb58b05fc4b22971 diff --git a/src/main.rs b/src/main.rs index 058f858..ff65a06 100644 --- a/src/main.rs +++ b/src/main.rs @@ -1,8 +1,11 @@ mod word_utils; +use std::collections::HashMap; + use word_utils::{first_word, second_word}; fn main() { + // strings and functions let s = String::from("Hello world"); println!("first word: '{}'", first_word(&s)); println!("second word: '{}'", second_word(&s).unwrap()); @@ -14,4 +17,51 @@ fn main() { Some(w) => println!("match: second word of '{}' exists: {}", s2, w), None => println!("match: second word of '{}' does not exist", s2), } + + // vectors + let v1 = vec![1, 2, 3]; + println!("statically initialized vector: {:?}", v1); + + let mut v2: Vec = Vec::new(); + v2.push("Hello".to_string()); + v2.push(String::from("world")); + println!("dynamically built vector: {:?}", v2); + println!("first element: {}", v2[0]); + for el in &mut v2 { + *el += "xx"; + } + for el in &v2 { + println!("{}", el); + } + + // hash maps + let mut scores = HashMap::new(); + scores.insert("john", 10); + scores.insert("mary", 20); + + println!("scores: {:?}", scores); + + // hash map with .collect() + let persons = vec![("homer", 42), ("marge", 30)]; + let collect_scores: HashMap<_, _> = persons.into_iter().collect(); + println!("collect_scores: {:?}", collect_scores); + + for (p, s) in &collect_scores { + println!("person {}: score {}", p, s); + } + + println!("john's score: {}", scores.get("john").unwrap()); + println!("jake's score: {}", scores.get("jake").unwrap_or(&-1)); + + // double scores + for (_, v) in scores.iter_mut() { + *v *= 2; + } + println!("scores after doubling: {:?}", scores); + + // double scores of immutable hashmap (rebuild it) + let collect_scores: HashMap<_, _> = collect_scores.iter() + .map(|(k, v)| (k, 2 * v)) + .collect(); + println!("collect_scores after rebuilding with doubling: {:?}", collect_scores); }