I have an array item like this:
var array = USA.NY[2];
// gives Albany
{USA : {
NY : [New York City, Long Island, Albany]
}}
I want to find the state from just having the array. How do I do this? Thanks.
function findParent(array) {
// do something
// return NY
}
In Javascript, array elements have no reference to the array(s) containing them.
To achieve this, you will have to have a reference to the 'root' array, which will depend on your data model.
Assuming USA is accessible, and contains only arrays, you could do this:
function findParent(item) {
var member, i, array;
for (member in USA) {
if (USA.hasOwnProperty(member) && typeof USA[member] === 'object' && USA[member] instanceof Array) {
array = USA[member];
for(i = 0; i < array.length; i += 1) {
if (array[i] === item) {
return array;
}
}
}
}
}
Note that I’ve renamed the array parameter to item since you’re passing along a value (and array item), and you expect the array to be returned.
If you want to know the name of the array, you should return member instead.
