joinTo

Builds a string representation of the array's elements, with configurable separator, prefix, postfix, element limit, and optional transform function. joinTo appends to an existing Appendable; joinToString returns a String directly.

Signatures

fun <T, D : Dimension, A : Appendable> MultiArray<T, D>.joinTo(
    buffer: A,
    separator: CharSequence = ", ",
    prefix: CharSequence = "",
    postfix: CharSequence = "",
    limit: Int = -1,
    truncated: CharSequence = "...",
    transform: ((T) -> CharSequence)? = null
): A

fun <T, D : Dimension> MultiArray<T, D>.joinToString(
    separator: CharSequence = ", ",
    prefix: CharSequence = "",
    postfix: CharSequence = "",
    limit: Int = -1,
    truncated: CharSequence = "...",
    transform: ((T) -> CharSequence)? = null
): String

Parameters

Parameter	Type	Description
`buffer`	`A : Appendable`	Target appendable (e.g., `StringBuilder`).
`separator`	`CharSequence`	String between elements. Default: `", "`.
`prefix`	`CharSequence`	String before the first element. Default: `""`.
`postfix`	`CharSequence`	String after the last element. Default: `""`.
`limit`	`Int`	Max elements to include. `-1` for all.
`truncated`	`CharSequence`	Shown when limit is exceeded. Default: `"..."`.
`transform`	`((T) -> CharSequence)?`	Custom element formatting. Default: `toString()`.

Returns: joinTo returns the buffer; joinToString returns a String.

Example

val a = mk.ndarray(mk[1, 2, 3, 4, 5])

a.joinToString()                           // "1, 2, 3, 4, 5"
a.joinToString(separator = " | ")          // "1 | 2 | 3 | 4 | 5"
a.joinToString(prefix = "[", postfix = "]") // "[1, 2, 3, 4, 5]"
a.joinToString(limit = 3)                  // "1, 2, 3, ..."
a.joinToString { (it * 10).toString() }    // "10, 20, 30, 40, 50"

28 February 2026