Microtasks versus tasks

<div class="v"><header>QUEUE ORDER <span>A → B → C</span></header><div class="stage queue"><div class="lanes"><div>script <b>A</b></div><div>Promise <b>B</b></div><div>timer <b>C</b></div></div><div class="console">output: <span id="out"></span><i id="cursor"></i></div></div><div class="muted">microtasks drain before next task</div></div>

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let i=0;function tick(){document.getElementById("out").textContent="A B C".slice(0,[1,3,5][i]);i=(i+1)%3}tick();setInterval(tick,750)