String di Rust

Rust punya dua tipe string utama yang sering membingungkan pemula:

String vs &str

Membuat String

let s1 = String::from("Halo");
let s2 = "Dunia".to_string();
let s3: &str = "literal";  // string literal = &str

Konversi

let owned: String = "hello".to_string();
let slice: &str = &owned;  // String → &str (deref coercion)
let owned2: String = slice.to_string();  // &str → String

Method String

let mut s = String::from("Hello");

s.push_str(", World!");       // append string
s.push('!');                  // append char
println!("{}", s.len());      // panjang dalam bytes
println!("{}", s.is_empty()); // false
println!("{}", s.contains("World"));  // true
println!("{}", s.to_uppercase());
println!("{}", s.to_lowercase());

let replaced = s.replace("Hello", "Hi");
println!("{}", replaced);

format! macro

let nama = "Budi";
let umur = 25;
let pesan = format!("{} berumur {} tahun", nama, umur);
println!("{}", pesan);

Split & Join

let csv = "apel,jeruk,mangga";
let buah: Vec<&str> = csv.split(',').collect();
println!("{:?}", buah);  // ["apel", "jeruk", "mangga"]

let joined = buah.join(" - ");
println!("{}", joined);  // "apel - jeruk - mangga"