javascript - 字符串长度未定义

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                                6年前关闭。
            
                    
我需要从表单输入中获取一个值。将其保存到var。获取用户输入的长度。我收到的不是字符数，而是undefined。两个警报均返回相同的undefined。为什么？

var aisbn = $('#aisbn').val();
alert(aisbn.lenght);
alert(aisbn.toString().lenght);

最佳答案

JavaScript不会自动进行拼写检查。

更改：

alert(aisbn.lenght);

至：

alert(aisbn.length);