通过如下代码展示解决该兼容性方案！
第一种：check2函数里面的方案可以针对option没有设置value和设置了value的情况
<html><head> <meta charset="utf-8"> <title>select</title></head><body>
<!-- A种情况 option未设置value --> <select name="select" id="select1"> <option selected="selected">Test1</option> <option >Test2</option> </select><!-- B种情况 option设置value -->
<select name="select2" id="select2"> <option value="Test1" selected="selected">Test1</option> <option value="Test2">Test2</option> </select><input type="button" value="我要试试" οnclick="check1()">
<input type="button" value="我要试试" οnclick="check2()">
<script> function check1() { //当上面option里没有设置value属性时 var value = document.getElementById("select1").options[document.getElementById("select1").options.selectedIndex].value, text = document.getElementById("select1").options[document.getElementById("select1").options.selectedIndex].text; console.log(value); console.log(text);}
function check2() { //当上面option里设置value属性时 var value = document.getElementById("select2").options[document.getElementById("select2").options.selectedIndex].value, text = document.getElementById("select2").options[document.getElementById("select2").options.selectedIndex].text; console.log(value); console.log(text);}
</script>
</body></html>
第二种：check1函数里面的方案可以针对option设置了value的情况
<html><head> <meta charset="utf-8"> <title>select</title></head>
<body>
<select name="select1" id="select1"> <option value="Test1" selected="selected">Test1</option> <option value="Test2">Test2</option> </select><input type="button" value="我要试试" οnclick="check1()">
<script> function check1(){ //当上面option里设置了value属性时 var select = document.getElementById("select1").value; console.log(select); console.log(document.getElementById("select1").options.selectedIndex); }</script>
</body></html>