Detect if parameter passed is an array? Javascript [duplicate]

javascript arrays arguments parameter-passing

if (param instanceof Array)    ...

Edit. As of 2016, there is a ready-built method that catches more corner cases, Array.isArray, used as follows:

if (Array.isArray(param))    ...

javascript arrays arguments parameter-passing

This is the approach jQuery 1.4.2 uses:

var toString = param.prototype.toString;var isArray = function(obj) {        return toString.call(obj) === "[object Array]";    }

javascript arrays arguments parameter-passing

I found this here:

function isArray(obj) {    return obj.constructor == Array; }

also this one

function isArray(obj) {    return (obj.constructor.toString().indexOf(”Array”) != -1);}

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