I want that the user can see the value of a variable by writing it's name in a textarea, simpliefied:
var money = "300$";
var input = "money"; //user wants to see money variable
alert(input); //This would alert "money"
Is it even possible to output (in this example) "300$"?
Thanks for help!
Instead of seprate variables, use an object as an associative array.
var variables = {
'money': '300$'
}
var input = 'money';
alert(variables[input]);
You can use an object and then define a variable on the go as properties on that object:
var obj = {}, input;
obj.money = "300$";
input = "money";
alert(obj[input]);
obj.anotherMoney = "400$";
input = "anotherMoney";
alert(obj[input]);
A simple way,you can still try this one :
var money = "300$";
var input = "money"; //user wants to see money variable
alert(eval(input)); //This would alert "money"
Here is an answer who use the textarea as asked.
JSFiddle http://jsfiddle.net/7ZHcL/
HTML
<form action="demo.html" id="myForm">
<p>
<label>Variable name:</label>
<textarea id="varWanted" name="varWanted" cols="30" rows="1"></textarea>
</p>
<input type="submit" value="Submit" />
</form>
<div id="result"></div>
JQuery
$(function () {
// Handler for .ready() called.
var variables = {
'money': '300$',
'date_now': new Date()
}
//Detect all textarea's text variation
$("#varWanted").on("propertychange keyup input paste", function () {
//If the text is also a key in 'variables', then it display the value
if ($(this).val() in variables) {
$("#result").html('"' + $(this).val() + '" = ' + variables[$(this).val()]);
} else {
//Otherwise, display a message to inform that the input is not a key
$("#result").html('"' + $(this).val() + '" is not in the "variables" object');
}
})
});
Related
Using jquery to get the value of a textbox.
BUT
i need to enter the id of the textbox, then use that value to get the value of the textbox using jquery.
var tt = $("#fieldname").val()
that works
now how do i enter the fieldname at runtime, and get jquery to execute the val command as if it was hard coded?
There are a few ways that you could do this. One way is to listen to one of the keyboard or change events on the textbox you enter the id into, to help determine when the input has changed. So for example
$("#inputText").on("keyup", function(keyupEvent){
var textboxId = $("#inputText").val();
var textboxIdValue = $("#" + textboxId).val();
});
Or another way could be to use a click event with similar kind of logic, so for example
$("#clickMe").on("click", function(){
var textboxId = $("#inputText").val();
var textboxIdValue = $("#" + textboxId).val();
})
An example for the use case of both can be seen here https://fiddle.jshell.net/xpvt214o/114584/
Here is an example for you to get started with:
<body>
<p>Type "one" or "two" below</p>
<input id="search" />
<input id="one" value="This input is #one" />
<input id="two" value="And this is #two" />
<p id="result">No input specified</p>
</body>
And the corresponding jQuery code:
// Cache jQuery elements for performance and readability
var $search = $("#search");
var $result = $("#result");
$search.on("change", function() {
var search_value = $search.val();
if (search_value.length) {
search_value = "#" + search_value.toLowerCase().trim(); // Sanitise user input
if ($(search_value).length) {
$result.text($(search_value).val());
} else {
$result.text("Input not found");
}
} else {
$result.text("No input specified");
}
});
This will show the value of the specified input, if it exists.
You can see it in action here: https://jsfiddle.net/jeevantakhar/xpvt214o/114558/
I have numeric values with many decimal places and the precision is required for other functions. I want to present the values in a form, so the user can change the values if necessary.
To increase the readability, I want to display the values rounded to 2 decimal places, but if the user clicks on an input field, the complete value should be presented. By doing this, the user can see the real value and adjust them better.
Example:
HTML
<button id="myBtn" onclick="fillForm()">Try it</button>
<form id="myForm" >
<fieldset>
<input type="text" id="myInput1" onchange="myFunction()" >
</fieldset>
</form>
JavasSript
<script>
//Example values that should be presented
var x = 3.14159265359;
function fillForm(){
document.getElementbyId("myInput1").value = x;
}
function myFunction(){
x = document.getElementbyId("myInput1");
}
</script>
The form input value should be " 3.14 " and if the user clicks in the field, the displayed value should be 3.14159265359.
Now the user can change the value and the new value has to be saved.
Because this is for a local 1 page website with no guaranty of internet connection, it would be an asset but not a requirement, to do it without an external script (jquery …).
you can use focus and blur event to mask/unmask you float, then simply store the original value in a data param, so you can use the same function to all input in your form ;)
function fillForm(inputId, val)
{
var element = document.querySelector('#'+inputId);
element.value = val;
mask(element);
}
function mask(element) {
element.setAttribute('data-unmasked',element.value);
element.value = parseFloat(element.value).toFixed(2);
}
function unmask(element) {
element.value = element.getAttribute('data-unmasked') || '';
}
<button onclick="fillForm('myInput1',3.156788)">Fill!</button>
<form id="myForm" >
<fieldset>
<input type="text" id="myInput1" onblur="mask(this)" onfocus="unmask(this)" >
</fieldset>
</form>
Edit: added "fillForm()" :)
Just use .toFixed(). It accepts one argument, an integer, and will display that many decimal points. Since Javascript primitives are immutable, your x variable will remain the same value. (also when getting/setting the value of an input use the .value property
function fillForm(){
document.getElementbyId("myInput1").value = x.toFixed(2);
}
If you need to save it you can store it in a new value
var displayX = x.toFixed(2)
Here is my solution. I hope you have other suggestions.
HTML
<form id="myForm" >
<fieldset>
<input type="text" id="myInput1" >
</fieldset>
</form>
<button id="myBtn" onclick="fill_form()">fill form</button>
JavasSript
<script>
var apple_pi = 10.574148541;
var id_form = document.getElementById("myForm");
//Event listener for form
id _form.addEventListener("focus", copy_input_placeh_to_val, true);
id _form.addEventListener("blur", round_input_2decimal, true);
id _form.addEventListener("change", copy_input_val_to_placeh, true);
// Replace input value with input placeholder value
function copy_input_placeh_to_val(event) {
event.target.value = event.target.placeholder;
}
// Rounds calling elemet value to 2 decimal places
function round_input_2decimal(event) {
var val = event.target.value
event.target.value = Number(val).toFixed(2);
}
// Replace input placeholder value with input value
function copy_input_val_to_placeh(event) {
event.target.placeholder = event.target.value;
}
// Fills input elements with value and placeholder value.
// While call of function input_id_str has to be a string ->
//fill_input_val_placeh("id", value) ;
function fill_input_val_placeh (input_id_str, val) {
var element_id = document.getElementById(input_id_str);
element_id.placeholder = val;
element_id.value = val.toFixed(2);
}
// Writes a value to a form input
function fill_form(){
fill_input_val_placeh("myInput1", apple_pi);
}
</script>
Here is an running example
https://www.w3schools.com/code/tryit.asp?filename=FLDAGSRT113G
Here is solution, I used focus and blur listeners without using jQuery.
I added an attribute to input named realData
document.getElementById("myInput1").addEventListener("focus", function() {
var realData = document.getElementById("myInput1").getAttribute("realData");
document.getElementById("myInput1").value = realData;
});
document.getElementById("myInput1").addEventListener("blur", function() {
var realData = Number(document.getElementById("myInput1").getAttribute("realData"));
document.getElementById("myInput1").value = realData.toFixed(2);
});
function fillForm(value) {
document.getElementById("myInput1").value = value.toFixed(2);
document.getElementById("myInput1").setAttribute("realData", value);
}
var x = 3.14159265359;
fillForm(x);
<button id="myBtn" onclick="fillForm()">Try it</button>
<form id="myForm" >
<fieldset>
<input type="text" id="myInput1" realData="" onchange="myFunction()" >
</fieldset>
</form>
jsfiddle : https://jsfiddle.net/mns0gp6L/1/
Actually there are some problems that needs to be fixed in your code:
You are redeclaring the x variable inside your myFunction function with var x =..., you just need to refer the already declared x without the var keyword.
Instead of using document.getElementById() in myFunction, pass this as a param in onchange="myFunction(this)" and get its value in the function.
Use parseFloat() to parse the value of your input to a float, and use .toFixed(2) to display it as 3.14.
This is the working code:
var x = 3.14159265359;
function fillForm() {
document.getElementById("myInput1").value = x.toFixed(2);
}
function myFunction(input) {
x = parseFloat(input.value);
}
To display the original number when you click on the input you need to use the onfocus event, take a look at the Demo.
Demo:
var x = 3.14159265359;
function fillForm() {
document.getElementById("myInput1").value = x.toFixed(2);
}
function focusIt(input){
input.value = x;
}
function myFunction(input) {
x = parseFloat(input.value);
}
<button id="myBtn" onclick="fillForm()">Try it</button>
<form id="myForm">
<fieldset>
<input type="text" id="myInput1" onchange="myFunction(this)" onfocus="focusIt(this)">
</fieldset>
</form>
The below code will update the display value enter by user in textbox when button clicked but in this code it will not preserve the previous value enter by user .
<h1>Type your comment below </h1>
<input id="txt_name" type="text" value="" />
<button id="Get">Submit</button>
<div id="textDiv"></div> -
<div id="dateDiv"></div>
jQuery(function(){
$("button").click(function() {
var value = $("#txt_name").val();
$("#textDiv").text(value);
$("#dateDiv").text(new Date().toString());
});
});
Now I want preserve all the value enter by user and when user will submit the button show both value previous as well as current.
How to achieve this ?
Can below code will help to preserve all the value
var $input = $('#inputId');
$input.data('persist', $input.val() );
If yes how to display all value previous,current etc. when user click on button ?
If i got this right, this is what you need?
<h1>Type your comment below </h1>
<input id="txt_name" type="text" value="" />
<button id="Get">Submit</button>
<script type="text/javascript">
jQuery(function(){
$("button").click(function() {
var value = $("#txt_name").val();
$("#section").prepend('<div class="textDiv">'+value+'</div>')
$("#section").prepend('<div class="dateDiv">'+new Date().toString()+'</div>')
$("#txt_name").val('');
});
});
</script>
<!-- each time you press submit, a new line will be pushed here -->
<div id="section">
</div>
If you want to display only the previous and current value the user submitted and use the data function then:
$("button").click(function() {
var input = $("#txt_name").val();
var previous = $("#textDiv").data('previous') || '';
$("#textDiv").text(previous+input);
$("#textDiv").data('previous',input);
$("#dateDiv").text(new Date().toString());
});
If you want all the values and you want to store them, then I would create an array. But you could always concatenate the string.
var arr = [];
$("button").click(function() {
var input = $("#txt_name").val();
arr.push(input);
var previous = $("#textDiv").data('previous') || '';
$("#textDiv").text(previous+input);
$("#textDiv").data('previous',previous+input);
$("#dateDiv").text(new Date().toString());
});
Without using .data() you can do this:
$("button").click(function() {
var input = $("#txt_name").val();
$("#textDiv").text($("#textDiv").text()+input);
$("#dateDiv").text(new Date().toString());
});
Instead of using two separate divs for message and date, you can use a single div.
<h1>Type your comment below </h1>
<input id="txt_name" type="text" value="" />
<button id="Get">Submit</button>
<div id="msgDiv"></div>
$(document).ready(function() {
var preservedTxt = '';
$("button").click(function() {
var input = $("#txt_name").val();
var date = new Date().toString();
var msg = input + ' - ' + date;
preservedTxt = preservedTxt + '<br>' + msg;
$('#msgDiv').html(preservedTxt);
});
});
Jsfiddle : https://jsfiddle.net/nikdtu/p2pcwj2f/
Storing values in array will help
jQuery(function(){
var name=[];
var time=[];
$("button").click(function() {
var value = $("#txt_name").val();
name.push(value);
$("#textDiv").text(name);
time.push(new Date().toString())
$("#dateDiv").text(time);
});
});
I am trying to get this Local Storage script to work.
I need First Name, Last Name and State. Can I only save one element? I have 3 lines set up, one for each element.
Also, I would like to use the jQuery append() method. So far I can only get an alert to work. alert(val); but that is not what I want and I can only get the last element to show...not first name, last name and state.
Here is my code:
<div id="message">
</div>
</p>
<p>
<script type="text/javascript">
function saveLocal(){
if (window.localStorage) {
localStorage.setItem("firstname","myfirstname");
localStorage.setItem("lastname","mylastname");
localStorage.setItem("lastname","state");
alert("The data has been saved locally.");
} else {
alert("Your Browser does not support LocalStorage.");
}
}
function readLocal(){
if (window.localStorage) {
var val = localStorage.getItem("firstname");
var val = localStorage.getItem("lastname");
var val = localStorage.getItem("state");
$("#message").empty().append(getVal());
}else {
alert("Your Browser does not support LocalStorage.");
}
}
</script>
</head>
<body>
<div id="main">
<input type="button" value="Save Values" onclick="saveLocal()"/>
<input type="button" value="Read Values" onclick="getVal()"/>
</div>
You are storing everything into one variable named val and you do not have method listed called getVal()
var val = localStorage.getItem("firstname"); //<-- val
var val = localStorage.getItem("lastname"); //<-- val
var val = localStorage.getItem("state"); //<-- val
$("#message").empty().append(getVal()); //<-- What is getVal()
I have several textfields which will populate a text area.
I managed to populate it with a javascript function. On the onblur event of a textfield, the value of the textfield is passed and the textarea is field with this value.
However, my problem is the following:
If I modify a previously filled textfield, the textarea will simply append it again.
What I need is some functionality that if:
1: If I give focus to the textfield which is already been filled and I don't modify it, it will not be appended (I implemented this with an if statement and substring.
2: If I modify a previously filled textfield, the text area DOES NOT append it again at the end of the string BUT it replaces the part of the textarea with just that text field new value.
Take for instance the following 2 textfields:
<input type="text" id="txtName" name="txtName" />
<input type="text" id="txtSurname" name="txtSurname" />
If I fill up these textfields with John and Doe respectively, the textarea value will become:
txtName=John,txtSurname="Doe"
I managed to implement this.
What I need is that if I edit txtName from John to Alex, the textarea value will be as follows:
txtName=Alex,txtSurname=Doe
and not like is currently being displayed, i.e.
txtName=John,txtSurname=Doe,txtName=Alex
Should I achieve this by using an array which will store all the textfields values?
Any help would be greatly appreciated.
Many thanks in advance.
the following code should work for you. I have wrapped the textboxes inside a div. and also registered a onkeyup event on both the textboxes.
The javascript code iterates through each textboxe inside the div, and prints its name and value in the textarea.
HTML
<div id="textBoxContainer">
<input type="text" id="txtName" onkeyup="UpdateTextArea();" name="txtName" />
<input type="text" id="txtSurname" onkeyup="UpdateTextArea();" name="txtSurname" />
</div>
<textarea id="textAreaResult"></textarea>
Javascript
<script type="text/javascript">
function UpdateTextArea() {
var textBoxContainerDiv = document.getElementById("textBoxContainer");
var textboxes = textBoxContainerDiv.getElementsByTagName("input");
var finalResult = "";
var textAreaFinalResult = document.getElementById("textAreaResult");
for (var i = 0; i < textboxes.length; i++) {
finalResult = finalResult + textboxes[i].id + "=" + textboxes[i].value + ",";
}
textAreaFinalResult.value = finalResult;
}
</script>
Hope this Helps! :)
For the record, I feel like this code is an ugly hack, but it should do the trick...
var fieldName = "txtName"; //your field name
var newValue = "Alex"; //your new value
var value = document.getElementById("my-textarea").value;
value = "," + value; //add a comma so we can ensure we don't replace the wrong value where the fieldname is a substring of another fieldname
if(value.indexOf("," + fieldName + "=") > 0) //see if a value is already defined
{
var index = value.indexOf("," + fieldName + "=") + fieldName.length + 2;
var start = value.substring(0, index); //get the portion before the value
var end = value.substring(index); //get everything else
if(end.indexOf(",") > 0)
{
end = end.substring(end.indexOf(",")); //remove the value by reducing the end to the location of the next comma
}else{
end = ""; //if there isn't another comma it was the last value in the list, so set the new end to nothing
}
value = start + newValue + end;
value = value.substring(1); //remove the starting comma we gave it
document.getElementById("my-textarea").value = value;
}else{
//append it to the end as you are already doing
}