X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/fff8ebeb3f0b84c71275cbb5adee0aad6114f79b..3b6f45e080b0d90f65a74f6c9534545d726a9432:/src/part03.rs?ds=sidebyside diff --git a/src/part03.rs b/src/part03.rs index ecb8b15..d8d71b1 100644 --- a/src/part03.rs +++ b/src/part03.rs @@ -50,12 +50,13 @@ fn read_vec() -> Vec { // access the "old" `line` again. let line = line.unwrap(); // Now that we have our `String`, we want to make it an `i32`. + //@ We first `trim()` the `line` to remove leading and trailing whitespace. //@ `parse` is a method on `String` that can convert a string to anything. Try finding it's documentation! //@ In this case, Rust *could* figure out automatically that we need an `i32` (because of the return type //@ of the function), but that's a bit too much magic for my taste. We are being more explicit here: //@ `parse::` is `parse` with its generic type set to `i32`. - match line.parse::() { + match line.trim().parse::() { //@ `parse` returns again a `Result`, and this time we use a `match` to handle errors (like, the user entering //@ something that is not a number). //@ This is a common pattern in Rust: Operations that could go wrong will return `Option` or `Result`.