Formal way of getting closest values in array in Javascript, given a value and a sorted array?

Question

If I have an array like this:

var array = [1, 3, 4, 5, 9, 10];

And I have a value like this:

var value = 8;

Answer 1

For array with sorted values (data is a matrix, xIndex is the column to search, xVal is the value to sarch for, threshold is the tolerated distance (maybe 0) ):

public static int getNearestValueIndex(double[][] data, int xIndex, Number xVal, int threshold){
    int indexMin = 0;
    int indexMax=data.length-1;

    int index;
    double val;
    double valToFind=xVal.doubleValue();
    double diff;
    index = (indexMax+indexMin)/2;
    while(index!=indexMin){

        val = data[index][xIndex];
        diff = Math.abs(valToFind-val);
        if(diff<=threshold) break;

        if(valxVal.doubleValue()){
            indexMax=index;
        }
        index = (indexMax+indexMin)/2;
    }
    val = data[index][xIndex];
    if(data.length>(index+1) && Math.abs(valToFind-val)> Math.abs(valToFind-data[index+1][xIndex])){
        index=index+1;
    }

    return index;
}