string.empty — Construct empty string arrays with MATLAB-compatible dimension semantics.

string.empty constructs empty string arrays, returning 0x0 by default. When dimensions are provided, it preserves MATLAB-compatible empty-shape semantics so the total element count remains zero.

Syntax

string.empty(n)

How string.empty works

• string.empty with no arguments yields a 0×0 string array.
• string.empty(n) produces a 0×n array. The leading dimension is fixed at 0, so the result is still empty even if n > 0.
• string.empty(m, n, p, ...) returns a 0×n×p×… array. All trailing dimensions are honoured while the leading dimension remains zero.
• You can provide a single size vector such as string.empty([0 5 3]); the first entry is ignored beyond confirming it is non-negative, and the remaining entries set the trailing dimensions.
• string.empty(___, 'like', prototype) copies the trailing dimensions from prototype when you do not supply explicit sizes. Any dimensions you pass explicitly take precedence. GPU-resident prototypes are automatically gathered so their shape can be inspected.
• Size inputs must be finite, real, non-negative integers. Fractional or negative values produce a MATLAB-compatible error.
• The result always resides on the host; there is no GPU counterpart for string arrays.

Does RunMat run string.empty on the GPU?

string.empty does not allocate or interact with GPU memory. It is a pure host constructor that instantly returns the requested shape metadata and an empty data buffer. When the runtime is executing under RunMat Accelerate, no provider hooks are invoked. 'like' prototypes that happen to live on the GPU are gathered to the host before their shape is examined.

GPU memory and residency

No. string.empty allocates metadata for an empty string array entirely on the host. Because the result contains no elements and string scalars are host-only, there is nothing to transfer to or from the GPU. Using gpuArray with string.empty has no effect and is unnecessary.

Examples

Creating a 0x0 string array

S = string.empty

Expected output:

S =
  0x0 string array

Building a 0xN string row vector

row = string.empty(5)

Expected output:

row =
  0x5 string array

Creating a 0xN string array with extra dimensions

cube = string.empty(0, 4, 3)

Expected output:

cube =
  0x4x3 string array

Using a size vector with string.empty

sz = [0 2 5];
grid = string.empty(sz)

Expected output:

grid =
  0x2x5 string array

Resetting a preallocated string array to empty

A = strings(3, 2);  % Some application-specific strings
A = string.empty(size(A))

Expected output:

A =
  0x2 string array

Preserving higher-dimensional layout while empty

layout = string.empty([2 0 4 6])

Expected output:

layout =
  0x0x4x6 string array

Reusing the shape of an existing array with 'like'

proto = strings(3, 2);
sameCols = string.empty('like', proto)

Expected output:

sameCols =
  0x2 string array

Using string.empty with coding agents

Open a RunMat example with live inputs, then ask the agent to explain how string.empty changes the result.

FAQ

Related Strings functions

Open-source implementation

Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how string.empty is executed, line by line, in Rust.

• View the source for string.empty in Rust on GitHub
• Learn how the RunMat runtime works
• Found a bug? Open an issue with a minimal reproduction.

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