arg2

Arg2 is a conventional placeholder name used in programming to denote the second argument passed to a function or command. It is not a defined language construct, but appears in examples, tutorials, and documentation to illustrate how a program handles multiple inputs.

In function signatures, arg1 and arg2 are common dummy parameter names. Examples in common languages show this usage: In C, int add(int arg1, int arg2) { return arg1 + arg2; } In Python, def add(arg1, arg2): return arg1 + arg2; In JavaScript, function add(arg1, arg2) { return arg1 + arg2; }. These examples are for illustration and do not imply special meaning in the language.

In command-line contexts, arg2 often refers to the second positional parameter provided by a user. For Bash scripts, the second argument is accessed as $2; in Python, the second command-line argument is sys.argv[2] (with sys.argv[0] being the script name). The exact indexing depends on the language and the convention used to represent the program’s arguments.

Naming and best practices: Because arg1 and arg2 are non-descriptive, many style guides discourage using such placeholders in real APIs or public code. Descriptive names, such as width and height, filename, threshold, or other semantically meaningful identifiers, improve readability and maintainability. When possible, rely on explicit parameter names or structured arguments parsed by a library to reduce ambiguity.

See also: parameter naming, positional argument, command-line argument, argument parsing.