检查文本框是否为空值

我有以下密码:

var inp = $("#txt");


if(inp.val() != "")
// do something

有没有其他方法可以使用变量‘ inp’检查空文本框

272842 次浏览

小开

if ( $("#txt").val().length > 0 )
{
// do something
}

Your method fails when there is more than 1 space character inside the textbox.

小开

最佳答案

if (inp.val().length > 0) {
// do something
}

if you want anything more complicated, consider regex or use the validation plugin which takes care of this for you

小开

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.

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$('input:text').filter(function() { return this.value.length > 0; });

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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.

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Use the following to check if text box is empty or have more than 1 white spaces

var name = jQuery.trim($("#ContactUsName").val());


if ((name.length == 0))
{
Your code
}
else
{
Your code
}

小开

Also You can use

$value = $("#txt").val();


if($value == "")
{
//Your Code Here
}
else
{
//Your code
}

Try it. It work.

小开

The check can be done like this:

if (!!inp.val()) {


}

and even shorter:

if (inp.val()) {


}