I want to know the type of the variable put in the function. So, I used typeof and like this:
randomFunctionName: function(obj){
switch(typeof obj){
case "object":
//Something
case "text":
//Something else
}
}
But the problem is, I can't tell if obj is an array or an object, since
typeof [] === "object" //true
typeof {} === "object" //true
So, how I can I separate them? Is there any difference between them?
An array is an object. You can test if an object is an array as follows:
Object.prototype.toString.apply(value) === '[object Array]';
You can wrap this up into a function as follows:
function isArray(a)
{
return Object.prototype.toString.apply(a) === '[object Array]';
}
[object Array] the same in every browser?
check the constructor:
[].constructor == Array //true
{}.constructor == Object //true
{}.constructor --> SyntaxError: Unexpected token .
Since ECMAScript 5 you can use the native method:
Array.isArray( maybeArray );
If compatibility is of concern you can use Underscore.js or jQuery:
_.isArray( maybeArray ); // will use the native method if available
$.isArray( maybeArray );
This kind of utility is also present in AngularJS.
This is pretty simple. Try something like
var to = {}.toString;
alert(to.call([])); //[object Array]
alert(to.call({})); //[object Object]
I would suggest, based on @Martin's answer:
// tests whether value is an object with curly braces
// (Arrays are objects too, but we don't want to include them)
const isAnObjectObject = (value) => {
return value.toString() === "[object Object]" && value !== "[object Object]"
}
nothingrelated.determine object or array