Get the value in an input text box

问题:

What are the ways to get and render an input value using jQuery?

Here is one:

<script type=\"text/javascript\" src=\"http://code.jquery.com/jquery-1.4.3.min.js\" ></script>
<script type=\"text/javascript\">
    $(document).ready(function(){
        $(\"#txt_name\").keyup(function(){
            alert($(this).val());
        });
    })
</script>

<input type=\"text\" id=\"txt_name\"  />

回答1:

//Get
var bla = $(\'#txt_name\').val();

//Set
$(\'#txt_name\').val(bla);

回答2:

You can only select a value with the following two ways:

// First way to get a value
value = $(\"#txt_name\").val(); 

// Second way to get a value
value = $(\"#txt_name\").attr(\'value\');

If you want to use straight JavaScript to get the value, here is how:

document.getElementById(\'txt_name\').value 

回答3:

There is one important thing to mention:

$(\"#txt_name\").val();

will return the current real value of a text field, for example if the user typed something there after a page load.

But:

$(\"#txt_name\").attr(\'value\')

will return value from DOM/HTML.

回答4:

You can get the value attribute directly since you know it\'s an <input> element, but your current usage of .val() is already the current one.

For the above, just use .value on the DOM element directly, like this:

$(document).ready(function(){
  $(\"#txt_name\").keyup(function(){
    alert(this.value);
  });
});

回答5:

I think this function is missed here in previous answers

.val( function(index, value) ) 

回答6:

You can get the value like this:

this[\'inputname\'].value

Where this refers to the form that contains the input.

回答7:

You have to use various ways to get current value of an input element.

METHOD - 1

If you want to use a simple .val(), try this:

<input type=\"text\" id=\"txt_name\" />

Get values from Input

// use to select with DOM element.
$(\"input\").val();

// use the id to select the element.
$(\"#txt_name\").val();

// use type=\"text\" with input to select the element
$(\"input:text\").val();

Set value to Input

// use to add \"text content\" to the DOM element.
$(\"input\").val(\"text content\");

// use the id to add \"text content\" to the element.
$(\"#txt_name\").val(\"text content\");

// use type=\"text\" with input to add \"text content\" to the element
$(\"input:text\").val(\"text content\");

METHOD - 2

Use .attr() to get the content.

<input type=\"text\" id=\"txt_name\" value=\"\" />

I just add one attribute to the input field. value=\"\" attribute is the one who carry the text content that we entered in input field.

$(\"input\").attr(\"value\");

METHOD - 3

you can use this one directly on your input element.

$(\"input\").keyup(function(){
    alert(this.value);
});

回答8:

To get the textbox value, you can use the jQuery val() function.

For example,

$(\'input:textbox\').val() – Get textbox value.

$(\'input:textbox\').val(\"new text message\") – Set the textbox value.

回答9:

For those who just like me are newbies in JS and getting undefined instead of text value make sure that your id doesn\'t contain invalid characters.

回答10:

You can simply set the value in text box.

First, you get the value like

var getValue = $(\'#txt_name\').val();

After getting a value set in input like

$(\'#txt_name\').val(getValue);