How to select multiple cells using ctrl + click

greenfield :

I have a table with numbers. When I click on a cell in the table, it toggles active state. I want to select one cell and press crtl and select another cell, and as result cells between first one and second will become active. How to implement it?

codepen https://codepen.io/geeny273/pen/GRJXBQP

<div id="grid">
  <div class="cell">1</div>
  <div class="cell">2</div>
  <div class="cell">3</div>
  <div class="cell">4</div>
  <div class="cell">5</div>
  <div class="cell">6</div>
</div>

const grid = document.getElementById("grid")

grid.onclick = (event) => {
  event.stopPropagation();
  const { className } = event.target;

  if (className.includes('cell')) {
    if (className.includes('active')) {
      event.target.className = 'cell';
    } else {
      event.target.className = 'cell active';
    }  
  }
}

It should work like shift highlighting and works in both directions

awran5 :

Try this:

const cells = document.querySelectorAll(".cell");
let lastClicked;

function handleClick(e) {
  // Toggle class active
  if (e.target.classList.contains("active")) {
    e.target.classList.remove("active");
  } else {
    e.target.classList.add("active");
  }

  // Check if CTRL key is down and if the clicked cell has aready class active
  let inRange = false;
  if (e.ctrlKey && this.classList.contains("active")) {
    // loop over cells
    cells.forEach(cell => {
      // check for the first and last cell clicked
      if (cell === this || cell === lastClicked) {
        // reverse inRange
        inRange = !inRange;
      }
      // If we are in range, add active class
      if (inRange) {
        cell.classList.add("active");
      }
    });
  }
  // Mark last clicked
  lastClicked = this;
}

cells.forEach(cell => cell.addEventListener("click", handleClick));

#grid {
  display: grid;
  grid-template-columns: repeat(3, 50px);
  grid-template-rows: repeat(2, 50px);
}

.cell {
  display: flex;
  justify-content: center;
  align-items: center;
  border: solid 1px #ccc;
}

.active {
  background-color: #80aaff;
}

<div id="grid">
  <div class="cell">1</div>
  <div class="cell">2</div>
  <div class="cell">3</div>
  <div class="cell">4</div>
  <div class="cell">5</div>
  <div class="cell">6</div>
</div>

codepen