node.js - Array.forEach / .map returning error when used with path.resolve -

i'm using nodejs 0.10.13. i'm curious behavior of following code snippet:

> var = ['1','2','3'] undefined > a.map(function(){return path.resolve(arguments[0])}) [ '/users/user/1',   '/users/user/2',   '/users/user/3' ] > a.map(path.resolve) typeerror: arguments path.resolve must strings     @ exports.resolve (path.js:313:15) > a.map(path.resolve.bind(path))) typeerror: arguments path.resolve must strings     @ exports.resolve (path.js:313:15) 

why 2nd , 3rd map calls return error when array has strings? going relevant line in nodejs's source code yields this:

if (typeof path !== 'string') {     throw new typeerror('arguments path.resolve must strings'); } else if (!path) {     continue; } 

which makes no sense why arguments not strings. have clue?

this happens because parameters passed each call of mapped function not actual elment, array index , whole array.

to see parameters gets sent map, try this:

> var = ['1', '2', '3']; ['1', '2', '3'] > a.map(function() { return arguments}); [ { '0': '1',     '1': 0,     '2': [ '1', '2', '3' ] },   { '0': '2',     '1': 1,     '2': [ '1', '2', '3' ] },   { '0': '3',     '1': 2,     '2': [ '1', '2', '3' ] } ] 

since object sent mapped function (path.resolve in case) not string object, typeerror.