joindelimiter

A join delimiter, or simply delimiter, is the string that separates elements when concatenating a sequence into a single text string. It is used in many programming and data-processing contexts to control how items are presented when merged.

Delimiters can be a single character, such as a comma or space, or a multi-character string like a semicolon followed by a space. They are not the values themselves but a formatting aid that defines the boundary between adjacent elements. Different languages and tools expose the delimiter as a parameter to a join or collapse operation, sometimes under different names such as separator or glue.

Common usage examples include:

- In Python, ", ".join(["apple","banana","cherry"]) yields "apple, banana, cherry".

- In JavaScript, ["a","b","c"].join("-") yields "a-b-c".

- In Java, String.join(", ", list) concatenates the elements with ", " as the delimiter.

- In SQL, STRING_AGG(column, ',') or GROUP_CONCAT(column) uses a delimiter to separate values in aggregate results.

- In R, paste(vec, collapse=", ") produces a single string with the elements joined by ", ".

Edge cases include handling empty sequences, which typically produce an empty string, and escaping or quoting when the delimiter may appear within elements (as in CSV formats). The choice of delimiter can affect readability and parsing, and in some contexts there are localization or standardization considerations. See also string joining and data serialization.