Question

我有这段代码：

First name:
<input id="first_name" name="firstname" type="text" placeholder="First Name" />
Last name:
<input id="last_name" name="lastname" type="text" placeholder="Last Name" />

<input id="search_order" type="Submit" value="Find Order" />

<span id="warning" style="visibility: hidden; color: red;">Please enter first and last name</span>

<script>
document.getElementById("search_order").addEventListener("click", search);
function search() {
    var fname = document.getElementById("first_name").value;
    var lname = document.getElementById("last_name").value;
    var name = fname + " " +  lname;
    if (fname == " " || lname == " ")
    {
        document.getElementById("warning").style.visibility = "visible";
        return;
    } else
        window.location = "http://bifoldsbidesign.com/?s=" + name + "&post_type=project";
}
</script>

即使使用If语句检查值是否为空，其中的搜索总是会经历？

如果有任何帮助，代码会在网站http://bifoldsbidesign.com/search-for-your-order/上生效。

Answer 1

如果您打算检查firstname和lastname是否为空，则应将其与""进行比较，而不是" "。后者在两个引号之间有一个空格。

＆＃13;

First name:
<input id="first_name" name="firstname" type="text" placeholder="First Name" /> Last name:
<input id="last_name" name="lastname" type="text" placeholder="Last Name" />

<input id="search_order" type="Submit" value="Find Order" />

<span id="warning" style="visibility: hidden; color: red;">Please enter first and last name</span>

<script>
  document.getElementById("search_order").addEventListener("click", search);

  function search() {
    var fname = document.getElementById("first_name").value;
    var lname = document.getElementById("last_name").value;
    var name = fname + " " + lname;
    if (fname == "" || lname == "") {
      document.getElementById("warning").style.visibility = "visible";
      return;
    } else
      window.location = "http://bifoldsbidesign.com/?s=" + name + "&post_type=project";
  }
</script>

＆＃13;

Answer 2

将您的条件更改为

if (fname.trim() == "" || lname.trim() == "")

您的条件将检查" "空格而不是空字符串。您也可以使用trim()不允许空格

＆＃13;

document.getElementById("search_order").addEventListener("click", search);
function search() {
    var fname = document.getElementById("first_name").value;
    var lname = document.getElementById("last_name").value;
    var name = fname + " " +  lname;
    if (fname.trim() == "" || lname.trim() == "")
        document.getElementById("warning").style.visibility = "visible";
    else
        window.location = "http://bifoldsbidesign.com/?s=" + name + "&post_type=project";
}

＆＃13;

First name:
<input id="first_name" name="firstname" type="text" placeholder="First Name" />
Last name:
<input id="last_name" name="lastname" type="text" placeholder="Last Name" />

<input id="search_order" type="Submit" value="Find Order" />

<span id="warning" style="visibility: hidden; color: red;">Please enter first and last name</span>

＆＃13;

Answer 3

您正在检查字段是否包含空格。你想要fname.trim() == ""
其中trim()首先删除所有空白字符，然后检查空字符串。

您还应将name的作业移至实际使用的其他作用域。

Javascript搜索验证

3 个答案: