Mitschrift Erste Lektion

src/main.rs

@@ -1,3 +1,62 @@
 fn main() {
-    println!("Hello, world!");
+//   _primitive_types();
+//   _compound_types();
+   _strings();
+}
+
+
+fn _primitive_types() {
+   // example int
+   let unsigned_32_bit: u32 = 4_294_967_295; // (0..2^32-1)
+   let signed_32_bit: i32 = -2_147_483_648; // (-2^31..2^31-1) (java int)
+   println!("integers (32 bit int). unsigned: {} | signed: {}", unsigned_32_bit, signed_32_bit);
+   // example int (long)
+   let unsigned_64_bit: u64 = 18_446_744_073_709_551_615; // (0..2^64-1)
+   let signed_64_bit: i64 = -9_223_372_036_854_775_808; // (-2^64..2^64-1) (java long)
+   println!("integers (32 bit int). unsigned: {} | signed: {}", unsigned_64_bit, signed_64_bit);
+   // floating point numbers
+   let float_32_bit: f32 = -1.1; // (java float)
+   let float_64_bit: f64 = -1.1; // (java double)
+   println!("floating point nubers. 23 bit: {} | 64 bit: {}", float_32_bit, float_64_bit);
+}
+
+
+fn _compound_types() {
+   // arrays
+   let fully_initialised: [f32; 2] = [-42.1, 69.1];
+   let dummy_initialised: [f32; 2] = [0.0, 0.0];
+   let [head, tail]: [f32;2] = fully_initialised;
+   println!("arrays. prefilled: {:?} | dummy valies: {:?}", fully_initialised, dummy_initialised);
+   println!("array items: 0: {} 1: {}", fully_initialised[0], fully_initialised[1]);
+   println!("array destructured: head: {} tail: {}", head, tail);
+   // tuples
+   let tuple: (&str, i32, f64) = ("tuple", 32, 1.1);
+   let (string, int, float): (&str, i32, f64) = tuple;
+   println!("tuple: {:?}", tuple);
+   println!("tuple items: 0: {} 1: {} 2: {}", tuple.0, tuple.1, tuple.2);
+   println!("tuple destructured: string: {} int: {} float: {}", string, int, float);
+}
+
+
+fn _strings() {
+   // string slice
+   let slice: &str = "Ich bin ein Slice";
+   let string: String = "Ich bin ein String".to_string();
+   println!("String slice: {} | String: {}", slice, string);
+   // conversion
+   let _string2: String = String::from("Ich bin ein String2");
+   let _dereferenced_string: &String = &string;
+   let _slice2: &str = string.as_str();
+   // concatenation
+   let concat: String = [slice, " und ", _slice2].concat();
+   println!("{}", concat);
+   // format
+   let format: String = format!("{} und {}", slice, string);
+   println!("{}", format);
+   // appending
+   let mut append: String = String::new(); // wichtig! mutable
+   append.push_str("Eine Zeile Text");
+   append.push(' ');
+   append = append + "mit suffix";
+   println!("{}", append);
 }