I have two arrays
["a", "b", "c"]
["a", "b", "d"]
I want to convert it to
{
a :
{
b :
{
c : null,
d : null
}
}
}
How can I do that?
-
YUI's JSON utility might be of help, I haven't put this as an answer though, because I couldn't tell you straight off the bat if it will cater to your needs. Or, come to think of it, check out YUI's augment utility, it merges objects I believe.danjah– danjah2010-09-07 22:13:16 +00:00Commented Sep 7, 2010 at 22:13
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1 Answer
var tree = {}
function addToTree(tree, array) {
for (var i = 0, length = array.length; i < length; i++) {
tree = tree[array[i]] = tree[array[i]] || {}
}
}
addToTree(tree, ["a", "b", "c"])
addToTree(tree, ["a", "b", "d"])
/*{
"a": {
"b": {
"c": {},
"d": {}
}
}
}*/
Only thing it doesn't do is set the leaves of the tree to null -- it sets them to an empty object. Is that ok?
If you want the leaves to be null, then use the following instead:
function addToTree(tree, array) {
for (var i = 0, length = array.length; i < length; i++) {
tree = tree[array[i]] = ((i == length - 1) ? null : tree[array[i]] || {})
}
}
// or, without the i == length - 1 check in each iteration:
function addToTree(tree, array) {
for (var i = 0, length = array.length; i < length -1; i++) {
tree = tree[array[i]] = tree[array[i]] || {};
}
tree[array[i]] = null;
}
/*{
"a": {
"b": {
"c": null,
"d": null
}
}
}*/
1 Comment
Marcel Korpel
Don't forget to use
var: var i = 0, length = array.length