1
<p id="demo">单击按钮舍入与“2.5”最接近的整数</p>2
<button onclick="myFunction()">点我</button>3
<script>4
function myFunction() {5
document.getElementById("demo").innerHTML = Math.round(2.5);6
}7
</script>
<p id="demo">单击按钮舍入与“2.5”最接近的整数</p><button onclick="myFunction()">点我</button><script> function myFunction() { document.getElementById("demo").innerHTML = Math.round(2.5); }</script>