Pierre Guilbert Pierre Guilbert - 7 months ago 11
Java Question

Is there clean syntax for checking if multiple variables all have the same value?

We have n variables

X = {x1,x2,...xn}
they are not in any structures whatsoever.

In python for example I can do that:
if (x1 == x2 == x3 == xn):


In java I must do:
if((x1 == x2) && (x2 == x3) && (x3 == xn)):


Do you know a simple way to improve this syntax? (Imagine very long variable name and lot of them)

Thanks.

Answer

If you have lots of these variables, have you considered putting them in a collection instead of having them as separate variables? There are various options at that point.

If you find yourself doing this a lot, you might want to write helper methods, possibly using varargs syntax. For example:

public static boolean areAllEqual(int... values)
{
    if (values.length == 0)
    {
        return true; // Alternative below
    }
    int checkValue = values[0];
    for (int i = 1; i < values.length; i++)
    {
        if (values[i] != checkValue)
        {
            return false;
        }
    }
    return true;
}

An alternative as presented by glowcoder is to force there to be at least one value:

public static boolean areAllEqual(int checkValue, int... otherValues)
{
    for (int value : otherValues)
    {
        if (value != checkValue)
        {
            return false;
        }
    }
    return true;
}

In either case, use with:

if (HelperClass.areAllEqual(x1, x2, x3, x4, x5))
{
    ...
}