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Get the id of input using it's name

I want to get the id of input using it's name,and to empty the input field.But it's not working.Is it possible?
html:
<input type="text" id="1" name="Color" maxlength="2" />
jQuery:
var myId="#";
myId=myId + $('[name="Color"]').attr('id');
$($myId).var('');

You can do this:
let id = $('input[name$="Color"]').val('').attr('id');
console.log(id);
$(`#${id}`).val('');
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" id="1" name="Color" maxlength="2" />

You can set the input value using the val() function.
<input type="text" id="1" name="Color" maxlength="2"/>
var myId='#' + $('[name="Color"]').attr('id');
$(myId).val('');
To get the input value use it like this:
$(myId).val();

Try this code.
const myId = $('input[name="Color"]').attr('id');
$("#"+myId).val(''); // you can set any value here or you can perform any other operations on this element -> $("#"+myId)
On first line of this JS code, we are getting id attribute and then on second line, we're using to manipulate element.
Now, if you want id only for performing some operations on that input element, you don't need to get id. You can also do like this.
let elem = $('input[name="Color"]');
elem.val(''); // only if same name is not used anywhere else.
I hope this helps you.

You can use attr directly to set a value. Moreover there is no need to append #.
let element = $('[name="Color"]');
console.log("before", element.attr('id'));
element.attr('id', null);
console.log("after", element.attr('id'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="text" id="1" name="Color" maxlength="2" />

Get the id of html page in jQuery?

I have an id on my page from that I have taken all the html by using .html() function in a variable .Now, I want to use the id from the variable in which I have stored the html. How can I do this in jQuery? I am not getting any idea. Please help me in this!
var idhtml= $("#id").html();
Like this, I have the html in idhtml
<input type="text" id="id1" name="id1" value="" class ="test" />
<input type="text" id="id2" name="id1" value="" class ="test" />
<input type="text" id="id3" name="id1" value="" class ="test" />
By idhtml, I want to get the id in the variable.

You can get the IDs like this:
$("input[id^='id']").each(function () {
console.log(this.id);
// Change the id:
$(this).attr("id", "new_id");
});
Select every input with an id that starts with id and for each input returned, print its ID in the console.

You can use .each().
To set the attribute you can use
1) .attr('attribute_name','attribute_value') or
2) .data('attribute_name','attribute_value')
with appropriate selector.
$("[name='id1']").each(function () {
console.log($(this).attr(id));
//to set the attr you can use
$(this).attr('attribute_name','attribute_value');
//to set custom attribute, use .data()
$(this).data('attribute_name','attribute_value');
});

try this
$(document).ready(function(){
var formId = $('form').attr('youId');
});

select particular input field name of particular form

i have some html code like this
<form name="first"><input name="firstText" type="text" value="General" />
<input name="secondText" type="text" value="General" />
<input name="ThirdText" type="text" value="General" />
<input name="FourthText" type="text" value="General" />
<input name="FifthText" type="text" value="General" />
</form>
<form name="second"><input name="firstText" type="text" value="General" />
<input name="secondText" type="text" value="General" />
<input name="ThirdText" type="text" value="General" />
<input name="FourthText" type="text" value="General" />
<input name="FifthText" type="text" value="General" />
</form>
i want to select "secondText" of form "second" using jquery or javascript and i want to change value of it using jquery.

Using jQuery:
var element = $("form[name='second'] input[name='secondText']");
Using vanilla JS:
var element = document.querySelector("form[name='second'] input[name='secondText']");
Changing the value: element.val(value) or element.value = value, depending of what you are using.

To the point with pure JS:
document.querySelector('form[name=particular-form] input[name=particular-input]')
Update:
This selector will return the input named "particular-input" inside form named "particular-form" if exists, otherwise returns null.
The selector filter "form[name=particular-form]" will look for all forms with name equals "particular-form":
<form name="particular-form">
The selector filter "input[name=particular-input]" will look for all input elements with name equals "particular-input":
<input name="particular-input">
Combining both filters with a white space, I mean:
"form[name=particular-name] input[name=particular-input]"
We are asking for querySelector(): Hey, find all inputs with name equals "particular-input" nested in all forms with name equals "particular-form".
Consider:
<form name="particular-form">
<input name="generic-input">
<input name="particular-input">
</form>
<form name="another-form">
<input name="particular-input">
</form>
<script>
document.querySelector('form[name=particular-form] input[name=particular-input]').style.background = "#f00"
</script>
This code will change the background color only of the second input, no matter the third input have same name. It is because we are selecting only inputs named "particular-input" nested in form named "particular form"
I hope it's more clear now.
;)
By the way, unfortunately I didn't found good/simple documentation about querySelector filters, if you know any reference, please post here.

// Define the target element
elem = jQuery( 'form[name="second"] input[name="secondText"]' );
// Set the new value
elem.val( 'test' );

Try
$("form[name='second'] input[name='secondText']").val("ENTER-YOUR-VALUE");

You can do it like this:
jQuery
$("form[name='second'] input[name='secondText']").val("yourNewValue");
Demo: http://jsfiddle.net/YLgcC/
Or:
Native Javascript
Old browsers:
var myInput = [];
myInput = document.getElementsByTagName("input");
for (var i = 0; i < myInput.length; i++) {
if (myInput[i].parentNode.name === "second" &&
myInput[i].name === "secondText") {
myInput[i].value = "yourNewValue";
}
}
Demo: http://jsfiddle.net/YLgcC/1/
New browsers:
document.querySelector("form[name='second'] input[name='secondText']").value = "yourNewValue";
Demo: http://jsfiddle.net/YLgcC/2/

You can try this line too:
$('input[name="elements[174ec04d-a9e1-406a-8b17-36fadf79afdf][0][value]"').mask("999.999.999-99",{placeholder:" "});

Add button in both forms. On Button click find nearest form using closest() function of jquery. then using find()(jquery function) get all input values. closest() goes in upward direction in dom tree for search and find() goes in downward direction in dom tree for search. Read here
Another way is to use sibling() (jquery function). On button click get sibling input field values.

Enable checkbox if text field is not empty with inconsistent id

Purpose is to have checkboxes disabled when the page loads, and remain greyed out until textbox is filled.
<input type="text" name="<%=commentID%>" />
<input type="checkbox" name="<%=SkipID%>" value="N" disabled/>
I tried to do something like
<input type="text" name="<%=commentID%>" onkeyup="userTyped('<%=SkipID%>') />
function userTyped(commen){
if(this.value.length > 0){
document.getElementById(commen).disabled=false;
}else{
document.getElementById(commen).disabled=true;
}
}
But it did not work. I am assuming because of the inconsistency of the name, but I have to have that.

You haven't given id to your html elements and is trying to use getElementById, which will return null. Javascript engine will not be able to set disabled attribute of null. Try setting id attribute, for elements as given below.
Also in your userTyped function you are referencing this. this here is the window object and not the input element. You need to pass the reference to input element to make this work, like this onkeyup="userTyped('<%=SkipID%>', this)"
Please find a possible correction below:
<input type="text" name="<%=commentID%>" id="<%=commentID%>" onkeyup="userTyped('<%=SkipID%>', this)" />
<input type="checkbox" name="<%=SkipID%>" id="<%=SkipID%>" value="N" disabled/>
/** commen is the id
* e is the input element
**/
function userTyped(commen, e){
if(e.value.length > 0){
document.getElementById(commen).disabled=false;
}else{
document.getElementById(commen).disabled=true;
}
}
jsFiddle here: http://jsfiddle.net/deepumohanp/dGS9H/

How do I replace part of the value of attributes for a set of elements in jQuery?

I am trying to replace a series of 'for' attributes of labels based on their current contents.
The application is using AJAX to add an item to an invoice without refreshing the page. Upon receiving notification of a successful item add, my script should replace all the labels in the form whose 'for' attribute ends with '-new' with the same attribute minus the '-new' and adding ('-' + itemValue), where itemValue is the item Id of the invoice item that was added.
I know how to select all the labels I want to change at once:
jQuery('label[for$=new]')
I know how to get their 'for' attribute:
jQuery('label[for$=new]').attr('for')
I tried the JavaScript replace method:
jQuery('label[for$=new]').attr('for').replace(/-new/,itemValue)
But that appears to select each label's 'for' attribute, replace the text, and pass the replaced text back (to nothing), since I don't know how to identify the labels that have the 'for' attribute I want to replace.
Here's some sample HTML:
<form id="InvoiceItemsForm-1" action="<?=$_SERVER['PHP_SELF'];?>" method="post" name="InvoiceItemsForm-1" onsubmit="return false">
<div id="InvoiceItem-new-1" class="InvoiceItem">
<label for="InvoiceItemNumber-new">New Invoice Item Number: </label>
<input id="InvoiceItemNumber-new" class="InvoiceItemNumber" type="text" value="" name="InvoiceItemNumber-new">
<label for="InvoiceItemDescription-new">Item Description: </label>
<input id="InvoiceItemDescription-new" class="InvoiceItemDescription" type="text" value="" name="InvoiceItemDescription-new">
<label for="InvoiceItemAmount-new">Item Amount: </label>
<input id="InvoiceItemAmount-new" class="InvoiceItemAmount" type="text" value="" name="InvoiceItemAmount-new">
<input id="addInvoiceItem-1" width="25" type="image" height="25" src="/payapp/images/greenplus.th.png" alt="Add New Invoice Item" onclick="addInvoiceItemButtonPushed(this)" value="invoiceItem">
</div>
<button id="CloseInvoice-1" onclick="closeInvoice(this)" type="button">Close Invoice</button>
</form>
Once I get this to work, I'm going to replace all the ids for all the inputs. Same problem. I imagine the solution looks something like this:
jQuery('input[id$=new]').attr('id').replace(/-new/,itemValue)
I just cannot figure out the syntax for this at all.

No need to use .each() ... the .attr() method accepts a function as the second parameter that returns the new value to be used as replacement
jQuery('label[for$=new]').attr('for', function(index, currentValue){
return currentValue.replace(/-new/,'-' + itemValue);
});

If I may, why not just put the input tag inside the label tag? That way, you won't need a for attribute inside the label tag.
Next, a better way to accomplish what you're trying to do would be to use the invoice ID number as the ID for the surrounding div, and add a 'new` class for "new" invoice entries.
So your form would look something like this:
<form id="InvoiceItemsForm-1" action="<?=$_SERVER['PHP_SELF']" method="post" name="InvoiceItemsForm-1" onsubmit="return false">
<div class="InvoiceItem new">
<label>New Invoice Item Number: <input class="InvoiceItemNumber" type="text" value="" name="InvoiceItemNumber"></label>
<label>Item Description: <input class="InvoiceItemDescription" type="text" value="" name="InvoiceItemDescription-new"></label>
<label for="InvoiceItemAmount-new">Item Amount: <input class="InvoiceItemAmount" type="text" value="" name="InvoiceItemAmount-new"></label>
<input id="addInvoiceItem-1" width="25" type="image" height="25" src="/payapp/images/greenplus.th.png" alt="Add New Invoice Item" onclick="addInvoiceItemButtonPushed(this)" value="invoiceItem">
</div>
<button id="CloseInvoice-1" onclick="closeInvoice(this)" type="button">Close Invoice</button>
</form>
You'll still have all the targetability you need to get the new invoice item field data, but now, you only have two things to do to convert from a "new" invoice row to an "existing" invoice item row: add an id attribute to the div and remove the new class, both of which jQuery will let you do quite easily.

Not sure I get the question, but something like:
var oldFor = $('label[for$=new]').attr('for');
var newFor = oldfor.replace(/-new/,itemValue);
$('label[for$=new]').attr('for', newFor);
.attr( attributeName, value )
attributeName = The name of the attribute to set.
value = A value to set for the attribute.
When selecting multiple elements, you will need to iterate:
$('label[for$=new]').each(function(index) {
$(this).attr('for', $(this).attr('for').replace(/-new/, '-' + itemValue));
});