How to use a variable inside a variable name c#

Question

I have 3 variables called gxpos, gypos and gzpos. I have a method called moove(), with a string argument axis (x, y or z) which I want to be able to change the value of both 3 variables (gxpos, gypos, gzpos).

In the code sample, I have represented the locations where I want to have the axis variable by this ?.

public void moove(string axis)
{ 
    g(?)pos = (?)pos + trkSizeStep.Value;
    if (g(?)pos != m(?)pos || -g(?)pos != m(?)pos)
    {
        (?)pos = g(?)pos;
        port.WriteLine(axis + (?)pos);
        lblpos(?).Text = (?)pos.ToString();
    }
    else
    {
        errorLimit(axis, 1);
    }
}

You can't do it like that. use vectors instead with numbers for x,y,z. — Mike Wise, Apr 16 '19 at 21:36
it is possible using reflection, it's just a really bad idea — Aydin, Apr 16 '19 at 21:39
What are you using this for? If it's unity or .net, both have classes that are already designed to handle 3-axis coordinates. — null, Apr 16 '19 at 21:43

score 0 · Answer 1 · answered Apr 16 '19 at 21:42

This is not possible in C# without reflection or the use of external tools such as T4 Templates.

However, you may be able to get around this by using arrays:

int[] gpos = new int[] { gxpos, gypos, gzpos };
int[] pos = new int[] { xpos, ypos, zpos };
int[] mpos = new int[] { mxpos, mypos, mzpos };
string axisNames = new string[] { "x", "y", "z" };

public void moove(int axis)
{
    gpos[axis] = pos[axis] + trkSizeStep.Value;
    if (gpos[axis] != mpos[axis] || -gpos[axis] != mpos[axis])
    {
        pos[axis] = gpos[axis];
        port.WriteLine(axisNames[axis] + pos[axis]);
        lblpos[axis].Text = pos[axis].ToString();
    }
    else
    {
        errorLimit(axisNames[axis], 1);
    }
}

Or better yet, take advantage of Vector<T> and friends

score 0 · Accepted Answer · answered Apr 16 '19 at 21:44

Using Dictionaries:

var gpos = new Dictionary<string, int> { { "x", 0 }, { "y", 0 }, { "z", 0 } };
var mpos = new Dictionary<string, int> { { "x", 0 }, { "y", 0 }, { "z", 0 } };
var pos = new Dictionary<string, int> { { "x", 0 }, { "y", 0 }, { "z", 0 } };
var lblpos = new Dictionary<string, Label> { { "x", lblxpos }, { "y", lblypos }, { "z", lblzpos } };

public void moove(string axis)
{
    gpos[axis] = pos[axis] + trkSizeStep.Value;
    if (gpos[axis] != mpos[axis] || -gpos[axis] != mpos[axis])
    {
        pos[axis] = gpos[axis];

        port.WriteLine(axis + pos[axis]);

        lblpos[axis].Text = pos[axis].ToString();

    }
    else
    {
        errorLimit(axis, 1);
    }
}

This works, but dictionaries by nature require a lot of overhead, which I'm not sure is necessary for this problem. — PC Luddite, Apr 16 '19 at 21:45
@PC Luddite I agree. If it was for myself I would use arrays like in your answer. — Theodor Zoulias, Apr 16 '19 at 21:51

How to use a variable inside a variable name c#

2 Answers2