// ./src/std/vec.md fn part0() { // Iterators can be collected into vectors let collected_iterator: Vec = (0..10).collect(); println!("Collected (0..10) into: {:?}", collected_iterator); // The `vec!` macro can be used to initialize a vector let mut xs = vec![1i32, 2, 3]; println!("Initial vector: {:?}", xs); // Insert new element at the end of the vector println!("Push 4 into the vector"); xs.push(4); println!("Vector: {:?}", xs); // Error! Immutable vectors can't grow // collected_iterator.push(0); // FIXME ^ Comment out this line // The `len` method yields the number of elements currently stored in a vector println!("Vector length: {}", xs.len()); // Indexing is done using the square brackets (indexing starts at 0) println!("Second element: {}", xs[1]); // `pop` removes the last element from the vector and returns it println!("Pop last element: {:?}", xs.pop()); // Out of bounds indexing yields a panic // println!("Fourth element: {}", xs[3]); // FIXME ^ Comment out this line // `Vector`s can be easily iterated over println!("Contents of xs:"); for x in xs.iter() { println!("> {}", x); } // A `Vector` can also be iterated over while the iteration // count is enumerated in a separate variable (`i`) for (i, x) in xs.iter().enumerate() { println!("In position {} we have value {}", i, x); } // Thanks to `iter_mut`, mutable `Vector`s can also be iterated // over in a way that allows modifying each value for x in xs.iter_mut() { *x *= 3; } println!("Updated vector: {:?}", xs); } pub fn main() { part0(); }