<script> var str = 'JavaScript'; console.log(str.toUpperCase());//小写转大写 console.log(str.toLowerCase());//大写转小写 </script>
<script> var str = 'JavaScript'; console.log(str.toUpperCase());//小写转大写 console.log(str.toLowerCase());//大写转小写 </script>
转载于:https://www.cnblogs.com/wuqiuxue/p/7682979.html