主页: <input type="url" id="myURL" maxlength="30">

<p>点击按钮获取 URL 字段maxlength属性值</p>

<button onclick="myFunction()">点我</button>

<p id="demo"></p>

<script>

function myFunction() {

    var x = document.getElementById("myURL").maxLength;

    document.getElementById("demo").innerHTML = x;

}

</script>

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