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function API: function.arguments (as per ES1 spec)

The arguments property of a function is an object that contains all the arguments passed to the function.

The arguments prop - discouraged since 1997 (and might not work)

WHEN reading arguments in the function body THEN it is an array-like object containing all parameters the function was called with
let args; const fn = function() { args = arguments; } fn(1, 'abc', {x: 'y'}); assert.deepStrictEqual(Array.from(args), [1, 'abc', {x: 'y'}]);
WHEN arguments is defined inside a function THEN this is NOT overridden
//: {"jskatas": {"runnerOptions": {"strictMode": false}}} const fn = function() { const arguments = 'arg'; return arguments; } assert.equal(fn('the argument'), 'arg');


The very first version of the spec defines this property already, the ES1 spec, see section (PDF 732kB).