Testing equality of vectors in a 2 dimensional array

p5.js Coding Questions
4

Here I am again…

I ended up not quite using the algorithm you provided. I may do so in the future and it may well be better than my algorithm, but…

  • I´m a beginner in js
  • I´m not (yet) comfortable with the idea and use of callback functions
  • I don´t fully understand the benefit of your algorithm compared to mine.

What did I do?

  addLines(cell) {
    for (let newLine of cell.neighbors) {
      // Suchen, ob es diese Zeile schon gibt
      let pushIt = true;
      for (let i = 0; i < this.lines.length; i++) {
        let lineExists = 0;
        for (let j = 0; j < newLine.length; j++) {

//          if (this.lines[i].includes(newLine[j])) {
//            //passenden Merker setzen
//            lineExists += 1;
//          }
          for (let k = 0; k < this.lines[i].length; k++) {
            if (this.lines[i][k].equals(newLine[j])) {
              //count number of identical vectors per line
              lineExists += 1;
            }
          }

        }
        // if all vectors are identical
        if (lineExists == newLine.length) {
          pushIt = false;
          break;
        }
      }
      if (pushIt) {
        this.lines.push(newLine);
      }
    }
  }

I added a 4th layer of nested loops to go throug the elements of the existing line(s) and the new line to compare them.
I used p5.Vector.equals() instead of == to compare the vectors. This is the core point I took from your suggestion and I´m sure it was my main mistake.

As far as I understand it the explicit check for same length in your function rowsContainSameVecs() is an improvement over my algorithm.
I think that one is minor in my special case, as I ensure lines of length 4 at creation of my inputs.
And your use of array.some() with your callback is presumably faster than my additional loop.

One point I don´t really understand is:
what does the “this” point to in the line

  const same = vec.equals(this);
```?