JSFiddle - React, Tailwind, and code Playground
HTML
<select>
<option value="-1">---</option>
<option value="alimentation">Choix 1</option>
<option value="2">Choix 2</option>
<option value="3">Choix 3</option>
<option value="4">Choix 4</option>
<option value="5">Choix 5</option>
<option value="6">Choix 6</option>
<option value="7">Choix 7</option>
<option value="8">Choix 8</option>
</select>
<div class="alimentation">Alimentation</div>
<div class="alimentation">Alimentation bis</div>
<div class="2">2</div>
<div class="3">3</div>
<div class="4">4</div>
<div class="5">5</div>
<div class="6">6</div>
<div class="7">7</div>
<div class="8">8</div>
JavaScript
function selectionDone(e){
var showAll = (e.target.value == "-1") ? 1 : 0,
i = 1,
l = select.children.length;
var divs, j, k;
for (; i<l; i++) {
divs = document.getElementsByClassName(select.children[i].value);
j = 0;
k = divs.length;
for(; j<k; j++) divs[j].style.display = (showAll) ? "block" : "none";
}
var toShow = document.getElementsByClassName(e.target.value);
j = 0;
k = toShow.length;
if (!showAll) for(; j<k; j++) toShow[j].style.display = "block";
}
var select = document.querySelector("select");
select.children[0].setAttribute("selected", "");
select.addEventListener("change", selectionDone, false);