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<!DOCTYPE html>
<html>
<body>
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<p>如果值为  +infinity、-infinity 或 NaN，则 isFinite() 函数返回 false，否则返回 true。</p>
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<p>请单击按钮以检查数字是否是有限的合法数字。</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 = isFinite(123) + "<br>";
  var b = isFinite(-1.23) + "<br>";
  var c = isFinite(5-2) + "<br>";
  var d = isFinite(0) + "<br>";
  var e = isFinite("123") + "<br>";
  var f = isFinite("Hello") + "<br>";
  var g = isFinite("2005/12/12");
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  var res = a + b + c + d + e + f + g;
  document.getElementById("demo").innerHTML = res;
}
</script>
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</body>
</html>
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