.. _op_ai_onnx_StringConcat:

StringConcat
============

- **Domain**: ``ai.onnx``
- **Since version**: 20

StringConcat concatenates string tensors elementwise (with NumPy-style broadcasting support)

**Inputs**

- **X** (*T*): Tensor to prepend in concatenation
- **Y** (*T*): Tensor to append in concatenation

**Outputs**

- **Z** (*T*): Concatenated string tensor

**Type Constraints**

- **T**: Inputs and outputs must be UTF-8 strings
  Allowed types: tensor(string).

Examples
--------

**test_cc_string_concat**

.. code-block:: text

    Inputs:
      x: shape=(3,), dtype=object
        ['abc', '', 'hello ']
      y: shape=(3,), dtype=object
        ['def', 'xyz', 'world']

    Outputs:
      z: shape=(3,), dtype=object
        ['abcdef', 'xyz', 'hello world']

**test_cc_string_concat_bcast**

.. code-block:: text

    Inputs:
      x: shape=(2, 2), dtype=object
        [['a', 'b'],
         ['c', 'd']]
      y: shape=(), dtype=object
        '!'

    Outputs:
      z: shape=(2, 2), dtype=object
        [['a!', 'b!'],
         ['c!', 'd!']]

**test_cc_string_concat_chained_3in_1out**

.. code-block:: text

    Inputs:
      x: shape=(3,), dtype=object
        ['abc', 'def', 'ghi']
      y: shape=(3,), dtype=object
        ['-', '/', '.']
      input_2: shape=(3,), dtype=object
        ['123', '456', '789']

    Outputs:
      tmp: shape=(3,), dtype=object
        ['abc-123', 'def/456', 'ghi.789']

**test_cc_string_concat_utf8**

.. code-block:: text

    Inputs:
      x: shape=(2,), dtype=object
        ['的', '中']
      y: shape=(2,), dtype=object
        ['的', '中']

    Outputs:
      z: shape=(2,), dtype=object
        ['的的', '中中']

**test_cc_string_concat_zero_dimensional**

.. code-block:: text

    Inputs:
      x: shape=(), dtype=object
        'cat'
      y: shape=(), dtype=object
        's'

    Outputs:
      z: shape=(), dtype=object
        'cats'