Sorting a list by three parameters (C#)

Questions & Answers
1

I have this list called “Block”. Each item has four parts being a string called “block”, and three floats for each coordinate:

public class Block : IComparable<Block>
{
	public string block;
	public float xLocation;
	public float yLocation;
	public float zLocation;
	
	public Block (string newBlock, float newXLocation, float newYLocation, float newZLocation)
	{
		block = newBlock;
		xLocation = newXLocation;
		yLocation = newYLocation;
		zLocation = newZLocation;	
	}
}

I want to order the blocks first by lowest x value, then lowest y value, and finally lowest z value.

So if I had this in the list:

  • “Stone”, -20, 30, 15
  • “Slope”, -20, 20, 50
  • “Stone”, 40, 5, 0
  • “Slope”, -20, 20, 10

It would end up like this:

  • “Slope”, -20, 20, 10
  • “Slope”, -20, 20, 50
  • “Stone”, -20, 30, 15
  • “Stone”, 40, 5, 0

Try to keep in mind I’m still not that good at Unity so if you can, try to provide some explanation on what the code is doing. Also I prefer C#.

Thanks in advance!

2

Your block class will need to have a CompareTo method. It would probably look something like this:

public int CompareTo(object otherObject)
{
    Block otherBlock = (Block) otherObject;
	
	if(this.xLocation < otherBlock.xLocation)
	{
		return -1;
	}
	else if(this.xLocation > otherBlock.xLocation)
	{
		return 1;
	}
	
	//the x matched, so lets check y
	if(this.yLocation < otherBlock.yLocation)
	{
		return -1;
	}
	else if(this.yLocation > otherBlock.yLocation)
	{
		return 1;
	}
	
	//the x and y matched, so lets check z
	if(this.zLocation < otherBlock.zLocation)
	{
		return -1;
	}
	else if(this.zLocation > otherBlock.zLocation)
	{
		return 1;
	}
	
	//everything matched, the two blocks are equal
	return 0;

}

Then you could have an list of Blocks and just call Sort() on the list. If you need more details on implementing IComparable I’d check out this tutorial:

http://www.codeproject.com/Articles/42839/Sorting-Lists-using-IComparable-and-IComparer-Inte