What is "newline"

n. (context computing English) The character or character sequence that indicates the end of a line of text and transition to the next line; ''or'', a control code or escape sequence used in a programming language to denote this character.

In computing, a newline, also known as a line ending, end of line (EOL), or line break, is a special character or sequence of characters signifying the end of a line of text and the start of a new line. The actual codes representing a newline vary across operating systems, which can be a problem when exchanging text files between systems with different newline representations.

The concepts of line feed (LF) and carriage return (CR) are closely associated, and can be either considered separately or together. In the physical media of typewriters and printers, two axes of motion, "down" and "across", are needed to create a new line on the page. Although the design of a machine (typewriter or printer) must consider them separately, the abstract logic of software can combine them together as one event. This is why a newline in character encoding can be defined as LF and CR combined into one (known variously as CR+LF, CRLF, LF+CR, or LFCR).

Some character sets provide a separate newline character code. EBCDIC, for example, provides an NL character code in addition to the CR and LF codes. Unicode, in addition to providing the ASCII CR and LF control characters, also provides a "next line" (NEL) control code, as well as control codes for "line separator" and "paragraph separator" markers.

Two ways to view newlines, both of which are self-consistent, are that newlines either separate lines or that they terminate lines. If a newline is considered a separator, there will be no newline after the last line of a file. Some programs have problems processing the last line of a file if it is not terminated by a newline. On the other hand, programs that expect newline to be used as a separator will interpret a final newline as starting a new (empty) line. Conversely, if a newline is considered a terminator, all text lines including the last are expected to be terminated by a newline. If the final character sequence in a text file is not a newline, the final line of the file may be considered to be an improper or incomplete text line, or the file may be considered to be improperly truncated.

In text intended primarily to be read by humans using software which implements the word wrap feature, a newline character typically only needs to be stored if a line break is required independent of whether the next word would fit on the same line, such as between paragraphs and in vertical lists. Therefore, in the logic of word processing, newline is used as a paragraph break and is known as a "hard return", in contrast to "soft returns" which are dynamically created to implement word wrapping and are changeable with each display instance. A separate control character called "manual line break" exists for forcing line breaks inside a single paragraph.