Question

I have a javascript array like var test = [2,5,8,12,56]; and now I want to search the closest next value of 9. So the output is 12 in this case (and not 8!).

Answer 1

Well here’s a simple way to do it:

function getNextVal(arr, val) {
    // omit the next line if the array is always sorted:
    arr = arr.slice(0).sort(function(a,b){return a-b;});

    for (var i=0; i < arr.length; i++)
        if (arr[i] >= val)
            return arr[i];

    // return default value when val > all values in array
}

You don’t say what to return if the search value is in the array, so I’ve assumed you want to return it. If by “closest next value” you meant that it should always return the next number higher than the search value change arr[i] >= val to use > instead of >=.

If you have a large array you probably want some kind of binary sort instead of just going through from the beginning.