firstOrNull

Returns the first value in this DataColumn. If the DataColumn is empty, returns null.

For more information: See firstOrNull on the documentation website.

See also first, last, take, takeLast, single.

Returns the first value in this DataColumn that matches the given predicate. Returns null if the DataColumn contains no elements matching the predicate (including the case when the DataColumn is empty).

Example

// In a DataFrame of financial transactions sorted by time,
// find the amount of the first transaction over 100 euros,
// or 'null' if there is no such transaction
df.amount.firstOrNull { it > 100 }

For more information: See firstOrNull on the documentation website.

See also first, last, take, takeLast, single.

Parameters

Returns the first row in this DataFrame. If the DataFrame does not contain any rows, returns null.

For more information: See firstOrNull on the documentation website.

See also first, last, take, takeWhile, takeLast, singleOrNull, that returns null unless there is exactly one row to return.

Returns the first row in this DataFrame that satisfies the given predicate. Returns null if the DataFrame contains no rows matching the predicate (including the case when the DataFrame is empty).

The predicate is a RowFilter — a lambda that receives each DataRow as both this and it and is expected to return a Boolean value.

It allows you to define conditions using the row's values directly, including through extension properties for convenient and type-safe access.

For more information, See RowFilter on the documentation website.

This can include column groups and nested columns.

Example

// In a DataFrame of financial transactions sorted by time,
// find the first transaction with amount over 100 euros,
// or 'null' if there is no such transaction
df.firstOrNull { amount > 100 }

For more information: See firstOrNull on the documentation website.

See also first, last, take, takeWhile, takeLast, singleOrNull, that returns null unless there is exactly one row to return.

Parameters