grid-auto-flow CSS property

grid-auto-flow: row;

grid-auto-flow: column;

grid-auto-flow: row dense;

<section class="default-example" id="default-example">
  <div class="example-container">
    <div class="transition-all" id="example-element">
      <div>One</div>
      <div>Two</div>
      <div>Three</div>
      <div>Four</div>
      <div>Five</div>
    </div>
  </div>
</section>

#example-element {
  border: 1px solid #c5c5c5;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  grid-template-rows: repeat(3, minmax(40px, auto));
  grid-gap: 10px;
  width: 220px;
}

#example-element > div {
  background-color: rgb(0 0 255 / 0.2);
  border: 3px solid blue;
}

#example-element > div:nth-child(1) {
  grid-column: auto / span 2;
}

#example-element > div:nth-child(2) {
  grid-column: auto / span 2;
}

/* Keyword values */
grid-auto-flow: row;
grid-auto-flow: column;
grid-auto-flow: dense;
grid-auto-flow: row dense;
grid-auto-flow: column dense;

/* Global values */
grid-auto-flow: inherit;
grid-auto-flow: initial;
grid-auto-flow: revert;
grid-auto-flow: revert-layer;
grid-auto-flow: unset;

<div id="grid">
  <div id="item1"></div>
  <div id="item2"></div>
  <div id="item3"></div>
  <div id="item4"></div>
  <div id="item5"></div>
</div>
<select id="direction">
  <option value="column">column</option>
  <option value="row">row</option>
</select>
<input id="dense" type="checkbox" />
<label for="dense">dense</label>

#grid {
  height: 200px;
  width: 200px;
  display: grid;
  gap: 10px;
  grid-template: repeat(4, 1fr) / repeat(2, 1fr);
  grid-auto-flow: column; /* or 'row', 'row dense', 'column dense' */
}

#item1 {
  background-color: lime;
  grid-row-start: 3;
}

#item2 {
  background-color: yellow;
}

#item3 {
  background-color: blue;
}

#item4 {
  grid-column-start: 2;
  background-color: red;
}

#item5 {
  background-color: aqua;
}

function changeGridAutoFlow() {
  const grid = document.getElementById("grid");
  const direction = document.getElementById("direction");
  const dense = document.getElementById("dense");
  let gridAutoFlow = direction.value === "row" ? "row" : "column";

  if (dense.checked) {
    gridAutoFlow += " dense";
  }

  grid.style.gridAutoFlow = gridAutoFlow;
}

const selectElem = document.querySelector("select");
const inputElem = document.querySelector("input");
selectElem.addEventListener("change", changeGridAutoFlow);
inputElem.addEventListener("change", changeGridAutoFlow);