ChatGPT解决这个技术问题 Extra ChatGPT

How do I get the value of text input field using JavaScript?

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?


a
a_horse_with_no_name

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

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


IE8 supports QSA as far as I can see, it just doesn't support CSS3 selectors in the selector string.
@FabrícioMatté i just checked here quirksmode.org/dom/tests/basics.html#querySelectorAll and it told me that it doesnot
Extremely helpful document, saved for reference. Thanks.
@GKislin Ah! I see. Nice that I didn't know about it. But after reading this, I am feeling reluctant to add this edit to the answer right now. Maybe someday later, I will add it with a warning to avoid it. One of all reasons for warning would be this. If you feel like it is really nice, then either make an edit with a warning or add another answer upon your wish :)
@calyxofheld Either use forEach or for loop over all of them. It is very basic thing in JS. Have you gone through JS briefly, if not? then I will recommend you to go through that first. Keep learning
m
maudulus
//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.


While I appreciate the completeness of the accepted answer, I found this answer to be of use re: accessing, in JS code, a value entered in a DOM text input element (text box). For detail, see my answer, elsewhere in this Question.
J
John Smith

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;


If you want it to be a proper javascript object so that you can programmatically access each property, just do: var input = JSON.parse(document.getElementById("input_id").value);
Simple and straight forward answer !!
v
viana

You should be able to type:

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

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.


D
Deepend

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.


Yes! I was surprised this simplicity. Have a look at realization of simple calculator 4stud.info/web-programming/samples/dhtml-calculator.html Are ther any reference for this javascript functiality, cause I before I always use jQuery or getElementById
N
Nimantha
<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>

K
Kamil Kiełczewski

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());


The edit is fine; commentary on downvotes doesn't belong in posts. Please refrain from rolling back when the post unlocks
b
bugwheels94

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.


D
Dhruv Raval

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>

L
Linh

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, ...


N
Nimantha

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; }


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

V
Valter Ekholm

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


S
Suraj Rao

simple js

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

N
Nimantha
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'.


C
C2121

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"