Alerting Javascript array object shows empty - php

Question

I am trying to send the JavaScript array to my php, but php gets empty [].
It even shows like that in my browser. I have always sent JSON and had no problem, but now have this format.
I have this example that makes no sense...it's just a code to illustrate the issue:
var blah = [];
var letters = ['a', 'b', 'c', 'd'];
for (var i = 0; i < letters.length; i++)
{
blah[letters[i]] = i;
}
Inside firebug DOM it shows as follows:
blah []
a 0
b 1
c 2
d 3
When I do
alert(blah) ------------------------------- I get empty
alert(JSON.stringify(blah)) ----- I get []
alert(blah.a) ---------------------------- I get 0
So how can I pass this object to php? Thanks

Answer 1

Instead of an array, try using an object.
So instead of:
var blah = [];
Try
var blah = {};

Answer 2

Arrays are continuously numerically indexed. They do not have strings as key names.
What you want is an object {}, not an array [].

Answer 3

Can not assign key value collection in array. You need to work on objects:
var obj = {
key1: value1,
key2: value2
};
for converting array to string you can use:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.toString();
with seperator:
var fruits = ["Banana", "Orange", "Apple", "Mango"];
var energy = fruits.join(" and ");
Here is working Demo
try this:
var blah = {};
var letters = ['a', 'b', 'c', 'd'];
for (var i = 0; i < letters.length; i++)
{
blah[letters[i]] = i;
}
alert(JSON.stringify(blah));

Answer 4

I have answered this before. Anyway, blah is an array, but you are not using it as array, you are using it as a hashmap. Arrays work with indexes and maps work with keys. Any object in JS can also act like a map. For e.g
var obj = new Object();
obj.a = 10;
obj["b"] = 20;
var obj2 = function(){...}
obj2.foo = 10;
obj2.bar = "baz";
Similarly, Array is also and Object and can act like a map. But when you use the array like a map, its array is not utilized to store the elements. They just act like above. So the length of an Array is 0 even though it has properties attached to it.
What you must do is use Array methods like push and pop to populate and retrieve from it.