Line Number

In computing, a line number is a method used to specify a particular sequence of characters in a text file. The most common method of assigning numbers to lines is to assign every line a unique number, starting at 1 for the first line, and incrementing by 1 for each successive line.

In the C programming language the line number of a source code line is one greater than the number of new-line characters read or introduced up to that point.

Line numbers were a required element of syntax in some older programming languages such as GW-BASIC. The primary reason for this is that most operating systems at the time lacked interactive text editors; since the programmer's interface was usually limited to a line editor, line numbers provided a mechanism by which specific lines in the source code could be referenced for editing, and by which the programmer could insert a new line at a specific point. Line numbers also provided a convenient means of distinguishing between code to be entered into the program and direct mode commands to be executed immediately when entered by the user (which do not have line numbers).

Largely due to the prevalence of interactive text editing in modern operating systems, line numbers are not a feature of most programming languages.

Read more about Line Number:  Line Numbers and Style, Line Numbers and GOTOs, Line Numbers and Syntax Errors

Famous quotes containing the words line and/or number:

    The line of separation was very distinct, and the Indian immediately remarked, “I guess you and I go there,—I guess there’s room for my canoe there.” This was his common expression instead of saying “we.” He never addressed us by our names, though curious to know how they were spelled and what they meant, while we called him Polis. He had already guessed very accurately at our ages, and said that he was forty-eight.
    Henry David Thoreau (1817–1862)

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    Milan Kundera (b. 1929)