​x
 
<!DOCTYPE html>
<html>
<body>
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<p>点击按钮可把不同的数字向下舍入为最接近的整数：</p>
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<button onclick="myFunction()">试一试</button>
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<p id="demo"></p>
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<script>
function myFunction() {
  var a = Math.floor(0.60);
  var b = Math.floor(0.40);
  var c = Math.floor(5);
  var d = Math.floor(5.1);
  var e = Math.floor(-5.1);
  var f = Math.floor(-5.9);
​
  var x = a + "<br>" + b + "<br>" + c + "<br>" + d + "<br>" + e + "<br>" + f;
  document.getElementById("demo").innerHTML = x;
}
</script>
​
</body>
</html>
​