如何使用 JavaScript 获取文本输入字段的值？

Question

I am working on a search with JavaScript. I would use a form, but it messes up something else on my page. I have this input text field:

<input name="searchTxt" type="text" maxlength="512" id="searchTxt" class="searchField"/>

And this is my JavaScript code:

<script type="text/javascript">
  function searchURL(){
    window.location = "http://www.myurl.com/search/" + (input text value);
  }
</script>

How do I get the value from the text field into JavaScript?

Answer 1

There are various methods to get an input textbox value directly (without wrapping the input element inside a form element):

Method 1:

document.getElementById('textbox_id').value to get the value of desired box

For example, document.getElementById("searchTxt").value;

Note: Method 2,3,4 and 6 returns a collection of elements, so use [whole_number] to get the desired occurrence. For the first element, use [0], for the second one use 1 , and so on...

Method 2:

Use document.getElementsByClassName('class_name')[whole_number].value which returns a Live HTMLCollection

For example, document.getElementsByClassName("searchField")[0].value; if this is the first textbox in your page.

Method 3:

Use document.getElementsByTagName('tag_name')[whole_number].value which also returns a live HTMLCollection

For example, document.getElementsByTagName("input")[0].value; , if this is the first textbox in your page.

Method 4:

document.getElementsByName('name')[whole_number].value which also >returns a live NodeList

For example, document.getElementsByName("searchTxt")[0].value; if this is the first textbox with name 'searchtext' in your page.

Method 5:

Use the powerful document.querySelector('selector').value which uses a CSS selector to select the element

For example, document.querySelector('#searchTxt').value; selected by id
document.querySelector('.searchField').value; selected by class
document.querySelector('input').value; selected by tagname
document.querySelector('[name="searchTxt"]').value; selected by name

Method 6:

document.querySelectorAll('selector')[whole_number].value which also uses a CSS selector to select elements, but it returns all elements with that selector as a static Nodelist.

For example, document.querySelectorAll('#searchTxt')[0].value; selected by id
document.querySelectorAll('.searchField')[0].value; selected by class
document.querySelectorAll('input')[0].value; selected by tagname
document.querySelectorAll('[name="searchTxt"]')[0].value; selected by name

Support

Browser          Method1   Method2  Method3  Method4    Method5/6
IE6              Y(Buggy)   N        Y        Y(Buggy)   N
IE7              Y(Buggy)   N        Y        Y(Buggy)   N
IE8              Y          N        Y        Y(Buggy)   Y
IE9              Y          Y        Y        Y(Buggy)   Y
IE10             Y          Y        Y        Y          Y
FF3.0            Y          Y        Y        Y          N    IE=Internet Explorer
FF3.5/FF3.6      Y          Y        Y        Y          Y    FF=Mozilla Firefox
FF4b1            Y          Y        Y        Y          Y    GC=Google Chrome
GC4/GC5          Y          Y        Y        Y          Y    Y=YES,N=NO
Safari4/Safari5  Y          Y        Y        Y          Y
Opera10.10/
Opera10.53/      Y          Y        Y        Y(Buggy)   Y
Opera10.60
Opera 12         Y          Y        Y        Y          Y

Useful links

1. To see the support of these methods with all the bugs including more details click here
2. Difference Between Static collections and Live collections click Here
3. Difference Between NodeList and HTMLCollection click Here

Answer 2

//creates a listener for when you press a key
window.onkeyup = keyup;

//creates a global Javascript variable
var inputTextValue;

function keyup(e) {
  //setting your input text to the global Javascript Variable for every key press
  inputTextValue = e.target.value;

  //listens for you to press the ENTER key, at which point your web address will change to the one you have input in the search box
  if (e.keyCode == 13) {
    window.location = "http://www.myurl.com/search/" + inputTextValue;
  }
}

See this functioning in codepen.

Answer 3

I would create a variable to store the input like this:

var input = document.getElementById("input_id").value;

And then I would just use the variable to add the input value to the string.

= "Your string" + input;

Answer 4

You should be able to type:

 var input = document.getElementById("searchTxt"); function searchURL() { window.location = "http://www.myurl.com/search/" + input.value; }

 <input name="searchTxt" type="text" maxlength="512" id="searchTxt" class="searchField"/>

I'm sure there are better ways to do this, but this one seems to work across all browsers, and it requires minimal understanding of JavaScript to make, improve, and edit.

Answer 5

Also you can, call by tags names, like this: form_name.input_name.value; So you will have the specific value of determined input in a specific form.

Answer 6

<input type="text" onkeyup="trackChange(this.value)" id="myInput">
<script>
function trackChange(value) {
    window.open("http://www.google.com/search?output=search&q=" + value)
}
</script>

Answer 7

Short

You can read value by searchTxt.value

 function searchURL() { let txt = searchTxt.value; console.log(txt); // window.location = "http://www.myurl.com/search/" + txt; ... } document.querySelector('.search').addEventListener("click", ()=>searchURL());

 <input name="searchTxt" type="text" maxlength="512" id="searchTxt" class="searchField"/> <button class="search">Search</button>

Answer 8

Tested in Chrome and Firefox:

Get value by element id:

<input type="text" maxlength="512" id="searchTxt" class="searchField"/>
<input type="button" value="Get Value" onclick="alert(searchTxt.value)">

Set value in form element:

<form name="calc" id="calculator">
  <input type="text" name="input">
  <input type="button" value="Set Value" onclick="calc.input.value='Set Value'">
</form>

https://jsfiddle.net/tuq79821/

Also have a look at a JavaScript calculator implementation: http://www.4stud.info/web-programming/samples/dhtml-calculator.html

UPDATE from @bugwheels94: when using this method be aware of this issue .

Answer 9

You can use onkeyup when you have more input field. Suppose you have four or input.then document.getElementById('something').value is annoying. we need to write 4 lines to fetch value of input field.

So, you can create a function that store value in object on keyup or keydown event.

Example :

<div class="container">
    <div>
        <label for="">Name</label>
        <input type="text" name="fname" id="fname" onkeyup=handleInput(this)>
    </div>
    <div>
        <label for="">Age</label>
        <input type="number" name="age" id="age" onkeyup=handleInput(this)>
    </div>
    <div>
        <label for="">Email</label>
        <input type="text" name="email" id="email" onkeyup=handleInput(this)>
    </div>
    <div>
        <label for="">Mobile</label>
        <input type="number" name="mobile" id="number" onkeyup=handleInput(this)>
    </div>
    <div>
        <button onclick=submitData()>Submit</button>
    </div>
</div>

javascript :

<script>
    const data={ };
    function handleInput(e){
        data[e.name] = e.value;
    }
    function submitData(){
        console.log(data.fname); //get first name from object
        console.log(data); //return object
    }
</script>

Answer 10

If your input is in a form and you want to get value after submit you can do like

<form onsubmit="submitLoginForm(event)">
    <input type="text" name="name">
    <input type="password" name="password">
    <input type="submit" value="Login">
</form>

<script type="text/javascript">

    function submitLoginForm(event){
        event.preventDefault();

        console.log(event.target['name'].value);
        console.log(event.target['password'].value);
    }
</script>

Benefit of this way: Example your page have 2 form for input sender and receiver information.

If you don't use form for get value then
- You can set 2 different id (or tag or name ...) for each field like sender-name and receiver-name , sender-address and receiver-address , ...
- If you set same value for 2 input, then after getElementsByName (or getElementsByTagName ...) you need to remember 0 or 1 is sender or receiver . Later if you change the order of 2 form in html, you need to check this code again

If you use form , then you can use name , address , ...

Answer 11

 function handleValueChange() { var y = document.getElementById('textbox_id').value; var x = document.getElementById('result'); x.innerHTML = y; } function changeTextarea() { var a = document.getElementById('text-area').value; var b = document.getElementById('text-area-result'); b.innerHTML = a; }

 input { padding: 5px; } p { white-space: pre; }

 <input type="text" id="textbox_id" placeholder="Enter string here..." oninput="handleValueChange()"> <p id="result"></p> <textarea name="" id="text-area" cols="20" rows="5" oninput="changeTextarea()"></textarea> <p id="text-area-result"></p>

Answer 12

<input id="new" >
    <button  onselect="myFunction()">it</button>    
    <script>
        function myFunction() {
            document.getElementById("new").value = "a";    
        }
    </script>

Answer 13

One can use the form.elements to get all elements in a form. If an element has id it can be found with .namedItem("id"). Example:

var myForm = document.getElementById("form1");
var text = myForm.elements.namedItem("searchTxt").value;
var url = "http://www.myurl.com/search/" + text;

Source: w3schools

Answer 14

simple js

function copytext(text) {
    var textField = document.createElement('textarea');
    textField.innerText = text;
    document.body.appendChild(textField);
    textField.select();
    document.execCommand('copy');
    textField.remove();
}

Answer 15

function searchURL() {
   window.location = 'http://www.myurl.com/search/' + searchTxt.value
}

So basically searchTxt.value will return the value of the input field with id='searchTxt' .

Answer 16

Short Answer

You can get the value of text input field using JavaScript with this code: input_text_value = console.log(document.getElementById("searchTxt").value)

More info

textObject has a property of value you can set and get this property.

To set you can assign a new value: document.getElementById("searchTxt").value = "new value"

Answer 17

If you are using jQuery then by using plugin formInteract, you just need to do this:

// Just keep the HTML as it is.

<input name="searchTxt" type="text" maxlength="512" id="searchTxt" class="searchField"/>

At bottom of the page just include this plugin file and write this code:

// Initialize one time at the bottom of the page.
var search= $("#searchTxt).formInteract();

search.getAjax("http://www.myurl.com/search/", function(rsp){
    // Now do whatever you want to with your response
});

Or if using a parameterized URL then use this:

$.get("http://www.myurl.com/search/"+search.get().searchTxt, {}, function(rsp){
    // Now do work with your response;
})

Here is the link to project https://bitbucket.org/ranjeet1985/forminteract

You can use this plugin for many purposes like getting the value of a form, putting values into a form, validation of forms and many more. You can see some example of code in the index.html file of the project.

Of course I am the author of this project and all are welcome to make it better.