# XO0169: match or select arms separated by `,` instead of newlines

`match` and `select` arms are separated by newlines, not commas, so arms read like statements. Remove the comma. See core 3.5.

## Example

```xo
fn f(b: Bool) -> Int {
  match b {
    true => 1,
    false => 2
  }
}
```

## Fix

```xo
fn f(b: Bool) -> Int {
  match b {
    true => 1
    false => 2
  }
}
```

Run `xo explain XO0169` for this text in a terminal, or see
[section 10.6 of the specification](../../spec/core/#106-diagnostic-codes).