The TEXTJOIN function in Google Sheets is used to combine multiple strings into a single string, with a specified delimiter between each string.

It concatenates the text values provided as arguments into one continuous text, separated by the specified delimiter.

The syntax for the TEXTJOIN function is as follows:

TEXTJOIN(delimiter, ignore_empty, text1, [text2, …])

delimiter: This is the character or string that you want to use as a separator between the text values. It can be a comma, space, hyphen, or any other character or string of characters . ignore_empty: This is a boolean value (TRUE or FALSE) that determines whether empty cells should be ignored or included in the resulting text. If set to TRUE, empty cells are ignored. If set to FALSE, empty cells are included.

text1, [text2, …]: These are the text values that you want to concatenate. You can provide multiple text values separated by commas.

Here's an example to illustrate how the TEXTJOIN function works:

=TEXTJOIN(", ", TRUE, "Apple", "Banana", "Orange")

In this example, the delimiter is a comma followed by a space.

The function will concatenate the strings "Apple," "Banana," and "Orange" with the delimiter between them, resulting in the output "Apple, Banana, Orange".

Note that the TEXTJOIN function is available in Google Sheets but may not be available in other spreadsheet software.