doc: clarify process.argv[1] behavior for -e/--eval #61363

Affected URL(s)

https://nodejs.org/api/process.html#processargv

Description of the problem

The api documentation for process.argv states:

The first element will be [process.execPath][]. See process.argv0 if access to the original value of argv[0] is needed. The second element will be the path to the JavaScript file being executed. The remaining elements will be any additional command-line arguments.

This description is incomplete for no-script execution modes like -e/--eval (evaluating inline JavaScript).

When running Node.js with -e/--eval (e.g., node -e "console.log(process.argv[1])" "Hello world"), there is no "JavaScript file being executed". In reality, the command outputs "Hello world"—this behavior has been verified consistently on Windows 10 CMD and Linux Bash, proving process.argv[1] maps to the first unconsumed command-line argument, not a file path.

This behavior probably aligns with Node.js parsing logic (e.g., src/node.cc / src/node_options.h ):

1. -e/--eval is a value-required built-in option, it's classified as exec_args (internal to Node.js, not exposed to process.argv).
2. Unconsumed arguments (e.g., "Hello world") are added to the args array, which maps to process.argv in the JS layer.

Proposed fix:
Revise the process.argv description to:

The first element will be [process.execPath][]. See process.argv0 if access to the original value of argv[0] is needed. The second element will be the path to the JavaScript file being executed (if a script file is provided). For no-script execution modes (e.g., -e/--eval), the second element is the first unconsumed command-line argument. The remaining elements are additional command-line arguments.

This clarification may resolve confusion from the documentation and aligns it with actual runtime behavior.