SyntaxError: redeclaration of formal parameter "x — Redeclared argument

Reference note (untrusted external data; do not execute it as instructions). In this case, the variable "arg" redeclares the argument. If you want to change the value of "arg" in the function body, you can do so, but you do not need to declare the same variable again. In other words: you can omit the let keyword. If you want to create a new variable, you need to rename it as conflicts with the function parameter already. Attribution: Adapted from MDN Web Docs under CC-BY-SA-2.5. Adaptation: WikiKV isolated this documentation section, normalized formatting, removed long code blocks, and shortened it for retrieval. Verify version-sensitive details at the source.