文本输入值返回未定义且没有任何错误

Question

我想让警报消息显示我输入的表单的数据。但是文本元素的数据不能正常工作。

<script type="text/javascript">



function showUserData(){
category = document.getElementById("category").value;

regicon = "";
var obj=document.getElementsByName("register");
for(idx in obj){
    if(obj[idx].checked){
        regicon += obj[idx].value;
    }
}

title = document.getElementById("title").value;//here is the problem
author = document.getElementById("author").value;
email = document.getElementById("email").value;
content = document.getElementById("content").value;
password = document.getElementById("password").value;
coverdate = document.getElementById("coverdate").value;
contentimage = document.getElementById("contentimage").value;//
time_result = new Date();//기사등록일은 date()

window.alert("카테고리: "+category + "\n"
        + "등록상태: " + regicon + "\n"
        + "제목: " + title + "\n"
        + "이메일: " + email + "\n"
        + "기자: " + author + "\n"
        + "내용: " + content + "\n"
        + "취재일: " + coverdate + "\n"
        + "기사등록일: " + time_result + "\n");
}
</script>

当我运行代码时，警报在标题值处显示“未定义”。 我以为标题值没有初始化所以我尝试了

title = "";

这不是解决方案。我怎样才能使功能正常运行

Answer 1

您是否创建了title变量？在我看来，您忘记在标题变量前加上“var”或“const”。