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<!DOCTYPE html>
<html>
<body>
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<h1>JavaScript 数组</h1>
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<p>计算数组中被四舍五入的数字的总和。</p>
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<p id="demo"></p>
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<script>
const numbers = [15.5, 2.3, 1.1, 4.7];
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document.getElementById("demo").innerHTML = numbers.reduce(getSum, 0);
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function getSum(total, num) {
  return total + Math.round(num);
}
</script>
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</body>
</html>
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