first

Returns the first element of the array, or the first element matching a predicate. Throws NoSuchElementException if the array is empty or no match is found; use firstOrNull for a safe variant that returns null instead.

Signatures

fun <T, D : Dimension> MultiArray<T, D>.first(): T

inline fun <T, D : Dimension> MultiArray<T, D>.first(
    predicate: (T) -> Boolean
): T

fun <T, D : Dimension> MultiArray<T, D>.firstOrNull(): T?

inline fun <T, D : Dimension> MultiArray<T, D>.firstOrNull(
    predicate: (T) -> Boolean
): T?

Parameters

Parameter	Type	Description
`predicate`	`(T) -> Boolean`	Condition to match the first element against.

Returns:

first(): the first element. Throws NoSuchElementException if the array is empty.
first(predicate): the first matching element. Throws NoSuchElementException if none match.
firstOrNull()/firstOrNull(predicate): same as above but returns null instead of throwing.

Example

val a = mk.ndarray(mk[10, 20, 30])

a.first()                // 10
a.first { it > 15 }      // 20
a.firstOrNull { it > 50 } // null

28 February 2026