jQuery 检查文本框是否有空值
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Check if textbox has empty value
提问by KJai
I have the following code:
我有以下代码：
var inp = $("#txt");
if(inp.val() != "")
// do something
Is there any other way to check for empty textbox using the variable 'inp'
有没有其他方法可以使用变量“inp”检查空文本框
回答by wiifm
if (inp.val().length > 0) {
// do something
}
if you want anything more complicated, consider regex or use the validation pluginwhich takes care of this for you
如果您想要更复杂的东西，请考虑使用正则表达式或使用为您处理此问题的验证插件
回答by Grimmy
var inp = $("#txt").val();
if(jQuery.trim(inp).length > 0)
{
//do something
}
Removes white space before checking. If the user entered only spaces then this will still work.
检查前删除空格。如果用户只输入空格，那么这仍然有效。
回答by rahul
if ( $("#txt").val().length > 0 )
{
// do something
}
Your method fails when there is more than 1 space character inside the textbox.
当文本框中的空格字符超过 1 个时，您的方法将失败。
回答by KAPIL SHARMA
Use the following to check if text box is empty or have more than 1 white spaces
使用以下命令检查文本框是否为空或有超过 1 个空格
var name = jQuery.trim($("#ContactUsName").val());
if ((name.length == 0))
{
Your code
}
else
{
Your code
}
回答by Tod
$('input:text').filter(function() { return this.value.length > 0; });
回答by Ricky Odin Matthews
if ( $("#txt").val().length == 0 )
{
// do something
}
I had to add in the == to get it to work for me, otherwise it ignored the condition even with empty text input. May help someone.
我必须添加 == 才能让它为我工作，否则即使输入空文本也会忽略条件。可能会帮助某人。
回答by Software Engineer
Also You can use
你也可以使用
$value = $("#txt").val();
if($value == "")
{
//Your Code Here
}
else
{
//Your code
}
Try it. It work.
尝试一下。这行得通。
回答by simhumileco
The check can be done like this:
检查可以这样完成：
if (!!inp.val()) {
}
and even shorter:
甚至更短：
if (inp.val()) {
}
