bots-garden/model-mellum · a1a9639

⑂ a1a9639

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k33g committed 2026-10-18T12:27:29+02:00 Browse files

a1a9639 parent: a9e95e5

added 06-struct-method.md +57 -0 Viewed

new file mode 100644
@@ -0,0 +1,57 @@
	1	+# How to Add a Greeting Method to the Human Structure
	2	+
	3	+What the reader will be able to do: Define a method on the `Human` struct that prints a personalized greeting.
	4	+
	5	+## Prerequisites
	6	+- Basic understanding of Rust structs and mutability (from previous tutorials)
	7	+- Familiarity with `fn main()` and `println!`
	8	+
	9	+## Steps
	10	+
	11	+1. Define the `Human` struct
	12	+ Open `src/main.rs` and ensure you have:
	13	+ ```rust
	14	+ struct Human {
	15	+ name: String,
	16	+ age: u32,
	17	+ }
	18	+ ```
	19	+
	20	+2. Add a method to the `Human` struct
	21	+ Replace the `main()` function with:
	22	+ ```rust
	23	+ impl Human {
	24	+ fn greet(&self) {
	25	+ println!("Hello, my name is {} and I am {} years old.", self.name, self.age);
	26	+ }
	27	+ }
	28	+
	29	+ fn main() {
	30	+ let person = Human {
	31	+ name: String::from("Alice"),
	32	+ age: 30,
	33	+ };
	34	+
	35	+ person.greet();
	36	+ }
	37	+ ```
	38	+
	39	+3. Compile and run
	40	+ Run:
	41	+ ```bash
	42	+ cargo run
	43	+ ```
	44	+ Expected output:
	45	+ ```
	46	+ Hello, my name is Alice and I am 30 years old.
	47	+ ```
	48	+
	49	+## Pitfalls
	50	+- Forgetting to use `self` in the method definition
	51	+- Using `&mut self` instead of `&self` when the method doesn't modify the struct
	52	+- Not implementing the `impl` block correctly (missing `fn` keyword)
	53	+
	54	+## To Go Further
	55	+- Learn how to implement multiple methods on the same struct
	56	+- Explore how to use `self` in different ways (`&self`, `&mut self`, `self`)
	57	+- Study how to return values from methods instead of printing them

++# How to Add a Greeting Method to the Human Structure
++
++What the reader will be able to do: Define a method on the `Human` struct that prints a personalized greeting.
++
++## Prerequisites
++- Basic understanding of Rust structs and mutability (from previous tutorials)
++- Familiarity with `fn main()` and `println!`
++
++## Steps
++
++1. **Define the `Human` struct**
++   Open `src/main.rs` and ensure you have:
++   ```rust
++   struct Human {
++       name: String,
++       age: u32,
++   }
++   ```
++
++2. **Add a method to the `Human` struct**
++   Replace the `main()` function with:
++   ```rust
++   impl Human {
++       fn greet(&self) {
++           println!("Hello, my name is {} and I am {} years old.", self.name, self.age);
++       }
++   }
++
++   fn main() {
++       let person = Human {
++           name: String::from("Alice"),
++           age: 30,
++       };
++
++       person.greet();
++   }
++   ```
++
++3. **Compile and run**
++   Run:
++   ```bash
++   cargo run
++   ```
++   Expected output:
++   ```
++   Hello, my name is Alice and I am 30 years old.
++   ```
++
++## Pitfalls
++- Forgetting to use `self` in the method definition
++- Using `&mut self` instead of `&self` when the method doesn't modify the struct
++- Not implementing the `impl` block correctly (missing `fn` keyword)
++
++## To Go Further
++- Learn how to implement multiple methods on the same struct
++- Explore how to use `self` in different ways (`&self`, `&mut self`, `self`)
++- Study how to return values from methods instead of printing them

modified hello_rust/src/main.rs +16 -6 Viewed

@@ -3,6 +3,15 @@ struct Human {
3	3	age: u32,
4	4	}
5	5
	6	+impl Human {
	7	+ fn greet(&self) {
	8	+ println!(
	9	+ "Hello, my name is {} and I am {} years old.",
	10	+ self.name, self.age
	11	+ );
	12	+ }
	13	+}
	14	+
6	15	fn main() {
7	16	println!("Hello, world!");
8	17
@@ -11,14 +20,15 @@ fn main() {
11	20	age: 30,
12	21	};
13	22
14		- println!("Name: {}", person.name);
15		- println!("Age: {}", person.age);
16		-
	23	+ // println!("Name: {}", person.name);
	24	+ // println!("Age: {}", person.age);
	25	+ person.greet();
	26	+
17	27	person.name = String::from("Bob");
18	28	person.age = 42;
19	29
20	30	println!("Some changes:");
21		- println!("Name: {}", person.name);
22		- println!("Age: {}", person.age);
23		-
	31	+ // println!("Name: {}", person.name);
	32	+ // println!("Age: {}", person.age);
	33	+ person.greet();
24	34	}

      age: u32,
  }
++impl Human {
++    fn greet(&self) {
++        println!(
++            "Hello, my name is {} and I am {} years old.",
++            self.name, self.age
++        );
++    }
++}
++
  fn main() {
      println!("Hello, world!");
          age: 30,
      };
--    println!("Name: {}", person.name);
++    // println!("Name: {}", person.name);
--    println!("Age: {}", person.age);
++    // println!("Age: {}", person.age);
--
++    person.greet();
++
      person.name = String::from("Bob");
      person.age = 42;
      println!("Some changes:");
--    println!("Name: {}", person.name);
++    // println!("Name: {}", person.name);
--    println!("Age: {}", person.age);
++    // println!("Age: {}", person.age);
--
++    person.greet();
  }