练习题选中变大写

不道归来`

于 2021-12-23 20:25:27 发布

阅读量159

点赞数 1

文章标签： javascript

本文链接：https://blog.youkuaiyun.com/qq_46342447/article/details/122115812

版权

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <input type="text">
    <script>
        var input=document.querySelector("input");
        input.addEventListener("select",selectHandler);


        function selectHandler(e){
            // console.log(input.value,input.selectionStart,input.selectionEnd)
            // input.value=input.value.slice(0,input.selectionStart)+input.value.slice(input.selectionStart,input.selectionEnd).toUpperCase()+input.value.slice(input.selectionEnd);

            input.value=input.value.split("").reduce(function(v,t,i){
                if(i>= input.selectionStart && i<input.selectionEnd) v+=t.toUpperCase();
                else v+=t;
                return v;
            },"");
        }
    </script>
</body>
</html>