JS array toggle push & splice

I have what I thought will be a simple task of 'toggling' a value to an array.

What I want to do is to add the row if it doesn't exist and delete if it does exist:

selected = new Array();

// repeated code
if(row in selected===true) selected.splice(row);
else selected.push(row);

Now this works fine with the exception of the first element in the array, which always remains unchanged and is apparently not recognized by the "in selected".

a) row = 1 > ["开发者_JAVA技巧1"]
b) row = 1 > ["1", "1"]
c) row = 2 > ["1", "1", "2"]
d) row = 2 > ["1", "1"]
e) row = 1 > ["1"]
f) row = 1 > ["1", "1"]

using the values and output above you can see that "1" gets added as the first element and never removed ??

---

the in operator and the slice method both take an index, not a value. i.e. rows = ["1", "2"] would be better expressed as

rows = []
rows[0] = "1";
rows[1] = "2";

so in the above example, 0 in rows returns true, because rows[0] exists.

Or, in your case, when rows = ["1"], 1 in rows returns false, because rows[1] does not exist. Then when rows = ["1", "1"], 1 in rows returns true because rows[1] exists, so you then remove it. etc etc.

instead of arrays and pushes, you could try just using objects....

var rows = {}

...

if(rows[selected]){
    rows[selected] = selected;
}
else{
    rows[selected] = null;
}