I got a structure like this:
var Array = new Array(3);
Array["123"] = ["a","b","c"];
Array["456"] = ["d","e","f"];
Array["789"] = ["g","h","i"];
for example, how do I get "b"
4 Answers
var a = new Array();
a["123"] = ["a","b","c"];
a["456"] = ["d","e","f"];
a["789"] = ["g","h","i"];
b = a["123"][1];
sample :) http://jsbin.com/agolef/1/edit
8 Comments
btiernay
I would use
[] instead of new Array() above, for the benefit of newbies reading these posts. (stackoverflow.com/questions/885156/…)
I Hate Lazy
@Asad: An Array is an object, and all Array indices are named properties.
@user1689607 I already know this. Read my comment again. I said he is treating
a as an object by adding named properties instead of numeric indices (which is a misuse of an Array type object). For example, checking a.length would yield 0, which could be unexpected for a new user. All array indices are named properties, but not all named properties are array indices.I Hate Lazy
@Asad: Right, and OP was only using indices. All the properties added in the OP would be used as indices of the Array. The
.length would not be 0. It would be 790. |
a["123"][1]; // yields "b"
a[123][1]; // also yields "b"
Indexing an array with a string is probably not what you meant to do.
var a = new Array(3);
a["123"] = ["a","b","c"]; // "123" causes the array to expand to [0..123]
a["123"][1]; // yields "b"
a[123] = ["a","b","c"]; // this has better performance and is idiomatic javascript.
a[123][1]; // also yields "b"
a["456"] = ["d","e","f"];
a["789"] = ["g","h","i"];
If you want to use an object as a map instead, try this:
a = new object()
a["123"] = ["a","b","c"];
a["123"][1]; // yields "b"
Comments
Use something like this (you don't need the quotes):
array[123][1]
Comments
Array is a native constructor. Using a new object that doesn't add properties to the native object:
var obj = {};
obj["123"] = ["a","b","c"];
obj["456"] = ["d","e","f"];
obj["789"] = ["g","h","i"];
obj["123"][1]; // "123"
What your code was doing was adding a bunch of properties to the native Array, (which is a function object that makes array objects). For more on the difference between arrays and other objects, see this question
4 Comments
I Hate Lazy
I didn't DV you, but I did see that you had 2 votes before you changed it. One was removed and then you got the DV.
I Hate Lazy
The code was not adding properties to the
Array constructor. It was overwriting the constructor with an Array instance (assuming the code was run in the global scope).I Hate Lazy
Well, that first line didn't have code formatting at first, so it was easy to overlook.
array[123][1]- assuming you named yourvar array, don't use capitals for variable names.