strings

hash_maps/Cargo.toml

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+[package]
+name = "hash_maps"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

hash_maps/src/main.rs

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+use std::collections::HashMap;
+
+fn main() {
+    use std::collections::HashMap;
+
+    let mut capitals = HashMap::new();
+
+    capitals.insert(String::from("Tokyo"), 43_000_000);
+    capitals.insert(String::from("Beijing"), 62_000_000);
+    capitals.insert(String::from("South Korea"), 29_000_000);
+
+    for (key, value) in &capitals {
+        println!("{key}: {value}")
+    }
+
+    let test1 = String::from("Tokyo");
+    let test2 = String::from("London");
+
+    let passing_test = get_population(capitals.clone(), test1);
+    let failing_test = get_population(capitals, test2);
+
+    println!(
+        "\npassing test: {:?}\nfailing test: {:?}",
+        passing_test, failing_test
+    );
+}
+
+fn get_population(capitals: HashMap<String, u32>, key: String) -> u32 {
+    let population = capitals.get(&key).copied().unwrap_or(0);
+    population
+}

strings/Cargo.toml

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+[package]
+name = "strings"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

strings/src/main.rs

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+fn main() {
+    // strings: collections of bytes with some useful methods
+
+    // akshually, Rust only has ONE string type in the core language
+    // the string slice 'str'
+    // string literals = stored in the binary
+    // string slices = reference to string data stored elsewhere
+    // it's all UTF-8 encoded under the hood
+
+    let s = "hello darkness".to_string();
+
+    let mut half = "my old ".to_string();
+
+    //using push_str() to append to a string
+    half.push_str("friend!");
+
+    // you can add strings using +...
+
+    let space = " ".to_string();
+
+    // let final_string = s + " " + ½
+    // let final_string = s + &space + ½
+    // println!("{}", final_string);
+
+    // ...or using format!()
+
+    let final_formatted_string = format!("{s}{space}{half}");
+    println!("{}", final_formatted_string);
+}
+
+// let hello = String::from("السلام عليكم");
+// println!("{}", hello);
+// let hello = String::from("Dobrý den");
+// println!("{}", hello);
+// let hello = String::from("Hello");
+// println!("{}", hello);
+// let hello = String::from("שלום");
+// println!("{}", hello);
+// let hello = String::from("नमस्ते");
+// println!("{}", hello);
+// let hello = String::from("こんにちは");
+// println!("{}", hello);
+// let hello = String::from("안녕하세요");
+// println!("{}", hello);
+// let hello = String::from("你好");
+// println!("{}", hello);
+// let hello = String::from("Olá");
+// println!("{}", hello);
+// let hello = String::from("Здравствуйте");
+// println!("{}", hello);
+// let hello = String::from("Hola");
+// println!("{}", hello);