实例代码“Ctrl+/”提示“F11/ESC”全屏 返回 格式化 恢复 运行
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<!DOCTYPE html>
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<html>
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<body>
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​
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<p>变量可以通过设置 <b>undefined</b> 来清空。</p>
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​
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<p id="demo"></p>
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​
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<script>
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var person = {firstName:"John", lastName:"Doe", age:50, eyeColor:"blue"};
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var person = undefined;
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document.getElementById("demo").innerHTML =
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person + "<br>" + typeof person;
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</script>
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​
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</body>
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</html>
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