JSFiddle - React, Tailwind, and code Playground

JavaScript

function f(v) {
	arguments[0] = null;
	if (arguments[0] === v) 
		alert('bug or feature?');
}

f(5);



function fStrict(v) {
    // In strict mode arguments are shallow copies as expected
    "use strict";
    arguments[0] = null;
	if (arguments[0] === v) 
		alert('bug or feature?');
}

fStrict(5);



function notEverythingIsReferenced(a, b) {
    a = "Hey Ho! :)";
    alert(arguments[0]);
    
    b = "Something else";
    // Not referenced because arguments[1] is not initialized in the first place ;)
    alert(arguments[1]);
}

notEverythingIsReferenced(23);