C# Enum Flags Comparison

Question

Given the following flags,

  [Flags]
    public enum Operations
    {
        add = 1,
        subtract = 2,
        multiply = 4,
        divide = 8,
        ev         


        

Answer 1

The reason your operation is failing is because you have the wrong expression. (Operations.add & Operations.eval) is always zero. Left and right side of your first comparison are both always zero. Try this instead - I suspect it's what you were after:

public double Evaluate(double input)
{
    if ((operation & (Operations.add | Operations.eval)) == (Operations.add | Operations.eval))
        currentResult += input;
    else if ((operation & (Operations.subtract | Operations.eval)) == (Operations.subtract | Operations.eval))
        currentResult -= input;
    else
        currentResult = input;

    operation = null;

    return currentResult;
}