includes / indexOf
Also written: includes, indexOf
Methods on strings and arrays: `includes(x)` answers `true` or `false`, and `indexOf(x)` gives the position or `-1` if it isn't there.
Also written: includes, indexOf
Methods on strings and arrays: `includes(x)` answers `true` or `false`, and `indexOf(x)` gives the position or `-1` if it isn't there.