indexOf
Returns the flat (row-major) index of the first occurrence of the specified element, or -1 if not found. Predicate-based variants (indexOfFirst, indexOfLast) and lastIndexOf are also available.
Signatures
fun <T, D : Dimension> MultiArray<T, D>.indexOf(element: T): Int
inline fun <T, D : Dimension> MultiArray<T, D>.indexOfFirst(
predicate: (T) -> Boolean
): Int
inline fun <T, D : Dimension> MultiArray<T, D>.indexOfLast(
predicate: (T) -> Boolean
): Int
fun <T, D : Dimension> MultiArray<T, D>.lastIndexOf(element: T): Int
Parameters
Parameter | Type | Description |
|---|---|---|
|
| The element to search for. |
|
| Condition to match elements against. |
Returns: Flat index (0-based), or -1 if not found.
Example
val a = mk.ndarray(mk[10, 20, 30, 20, 10])
a.indexOf(20) // 1
a.lastIndexOf(20) // 3
a.indexOfFirst { it > 15 } // 1
a.indexOfLast { it > 15 } // 3
a.indexOf(99) // -1
28 February 2026