I am trying to make a simple calculator. You enter one number, you enter the second one, press PLUS and get alert with an answer. I need to show alert('no data') if you click on PLUS when input fields are not touched.
function num1() {
nm = document.getElementById('nsum1').value;
}
function num2() {
mn = document.getElementById('nsum2').value;
}
function plus() {
sum = +nm + +mn;
if (nm == null || mn == null) {
alert('no data');
} else {
alert(sum);
}
}
<input onchange="num1()" id="nsum1" name="numb" type="tel" placeholder="number" maxlength="6" />
<span onclick="plus()" id="sum">PLUS</span>
<input onchange="num2()" id="nsum2" name="numb" type="tel" placeholder="number" maxlength="6" />
So far I have tried if(sum == undefined)/if(sum == null)/if(sum == false)/if(isNaN(sum))/if(sum == "") and nothing seems to work.
If you haven't touched the input field and get the value, then the result would be ""
You need a condition like
if (nm == "" || mn == "") {
alert('no data');
}
And also you should do operation after validations. You are doing operation and then validating.
Fixed other issues aswell.
function plus() {
mn = document.getElementById('nsum2').value;
nm = document.getElementById('nsum1').value;
if (nm == "" || mn == "") {
alert('no data');
} else {
sum = +nm + +mn;
alert(sum);
}
}
<input id="nsum1" name="numb" type="tel" placeholder="number" maxlength="6" />
<span onclick="plus()" id="sum">PLUS</span>
<input id="nsum2" name="numb" type="tel" placeholder="number" maxlength="6" />
You can do it much easier
function plus(num1, num2) {
alert(isNaN(num1) || isNaN(num2) ? 'No data' : num1 + num2);
}
function getNumber(id) {
return parseFloat(document.getElementById(id).value);
}
<input id="nsum1" type="number" placeholder="number" maxlength="6" />
<span onclick="plus(getNumber('nsum1'), getNumber('nsum2'))" id="sum">PLUS</span>
<input id="nsum2" type="number" placeholder="number" maxlength="6" />
I've made some changes to your code to make it more robust. See the inline comments for a description.
Declare variables
It is important to declare your variables, when you don't all the variables you are using will wind up in the global scope. When you Google this you will find many articles like this one: https://gist.github.com/hallettj/64478.
Prevent polluting the global scope. In a small website this may not be much of an issue but when working on larger project or with third party code, this is a must. The link above also explains this to some extend.
Use a button If you want something to be interactive, use an HTML element that was meant for it. The button element should be used, it has all sorts of accessibility features the span doesn't have. For instance, by default it will receive focus when navigating your website with the tab key.
Use descriptive variable names nm and mn may mean something to you now but in 6 months it will be a complete mystery. It also makes the code more readable and thus easier to maintain.
Attach event listeners in JS In general it is a bad idea to assign event listeners through the HTML attribute onXXX="". It is more error prone and a lot more time intensive when you want to change something.
// Wrap your code in a closure to prevent poluting the global scope.
(function() {
// Always declare your variables. These variables are no longer scoped to the window object but are no scoped to the function we're in.
var
valueA = null,
valueB = null;
/**
* To check if your input is a valid number requires a couple of checks.
* It is best to place these into their own method so you're other
* method is more readable.
*/
function isNumber(value) {
if (
// == null checks for undefined and null
value == null ||
value === '' ||
isNaN(value)
) {
return false;
}
return true;
}
function onChangeHandler(event) {
var
// Get the element that dispatched the event.
target = event.target;
// Check if the target has the class we've assigned to the inputs, of not you can ignore the event.
if (!target.classList.contains('js-input')) {
return;
}
// Based on the ID of the target, assign the value to one of the variables for the values.
switch(target.id) {
case 'nsum1':
valueA = parseFloat(target.value);
break;
case 'nsum2':
valueB = parseFloat(target.value);
break;
}
}
function onSumTriggerClicked(event) {
// Check if there are numbers to work with
if (
!isNumber(valueA) ||
!isNumber(valueB)
) {
// If not alert the user
alert('no data');
return;
}
sum = valueA + valueB;
alert(sum);
}
function init() {
var
// Get the calculator element.
calculator = document.getElementById('calculator'),
// Get the button to sum up the value.
sumButton = document.getElementById('sum-trigger');
// Add an event listener for the change event.
calculator.addEventListener('change', onChangeHandler);
// Add an event listener for the click event.
sumButton.addEventListener('click', onSumTriggerClicked);
}
// Call the init method.
init();
})();
<div id="calculator">
<input class="js-input" id="nsum1" name="numb" type="tel" placeholder="number" maxlength="6" />
<button type="button" id="sum-trigger" id="sum">PLUS</button>
<input class="js-input" id="nsum2" name="numb" type="tel" placeholder="number" maxlength="6" />
</div>
Try to track it via Inspector, maybe log the values of nm and mn before anything else and correct your condition accordingly(as the sample).
function plus() {
console.log(nm);
sum = +nm + +mn;
if (nm == null || mn == null) {
alert('no data');
}
It will most likely just be blank. So in this case you can modify your condition into:
if (nm === '' || mn === '') {...}
Hope it will help
Please use this as reference.
I've fixed your code.
if ( num1 === '' && num2 === '' ) {
alert('no data');
} else {
alert( parseInt(num1) + parseInt(num2) );
}
Related
I have a phone number input that I am trying to get the dashes to appear in the number as the user types.
I am wanting the number to appear as 555-555-5555.
The function works for the most part, but the dashes aren't entered until after the whole number is entered. I am using the keyup function, which I thought would solve this, but no luck.
Does anyone have any recommendations as to what I have to do to get the dashes to be entered as the user types in the digits?
$('#phone').keyup(function() {
$(this).val($(this).val().replace(/(\d{3})\-?(\d{3})\-?(\d{4})/,'$1-$2-$3'))
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div>
<label class="contact-label">Phone Number:</label>
<input type="tel" class="contact_input" name="phone" id="phone">
</div>
I modified your code slightly to produce something that I think is a little easier to read, but still does the job.
I just evaluated the length of the <input /> tag's value on each .keyup() event and then augmented the value accordingly. Take a look at the snippet below:
--UPDATE--
After comments regarding backspacing issues I added a couple lines of code that seem to fix the issue:
First I checked for either backspace or delete .keyup() events to prevent the formatting code from interfering with correcting errors in the number.
I also added a few checks, and a global formatFlag variable to ensure that if the user backspaces to an awkward index like 3 or 6(where hyphens would normally be added), that formatting would resume as normal on the next .keyup() event.
let formatFlag = false;
$(function(){
$('#phone').keyup(function(evt) {
let modifiedValue = $(this).val().replace(/-/g, "");
if(evt.keyCode == 8 || evt.keyCode == 46) { //8 == backspace; 46 == delete
//Checks whether the user backspaced to a hyphen index
if(modifiedValue.length === 3 || modifiedValue.length === 6) {
//Checks whether there is already a hyphen
if($(this).val().charAt($(this).val().length - 1) !== '-') {
formatFlag = true; //Sets the format flag so that hyphen is appended on next keyup()
} else {
return false; //Hyphen already present, no formatting necessary
}
} else {
formatFlag = false;
}
return false; //Return if backspace or delete is pressed to avoid awkward formatting
}
if(!!formatFlag) {
// This re-formats the number after the formatFlag has been set,
// appending a hyphen to the second last position in the string
$(this).val($(this).val().slice(0, $(this).val().length - 1) + '-' +
$(this).val().slice($(this).val().length - 1));
formatFlag = false; //Reset the formatFlag
}
if(modifiedValue.length % 3 == 0) {
if(modifiedValue.length === 0 || modifiedValue.length >= 9){
return false;
} else {
$(this).val($(this).val() + '-');
return;
}
}
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div>
<label class="contact-label">Phone Number:</label>
<input type="tel" class="contact_input" name="phone" id="phone" />
</div>
I'm using pure JS to try to add a class to a number input when the input has a value. The first part of the JS (which adds the "checked" state) is working, but the portion that adds the class name ("selected") isn't being applied. Any ideas what I'm doing wrong?
This is a combined radio and number input, hence the extra input type.
function select_radio_item_other_button(text_obj, radio_but)
{
if (document.getElementById)
{
el = document.getElementById(radio_but);
if (el.checked)
return;
if (text_obj.value != '')
el.checked = true;
text_obj.className += " selected";
}
}
And the HTML
<div class="other">
<input type="radio" name="radio_21" id="radio_21_22" checked="checked">
<label for="radio_21_22" id="radio_21_22_amt">
<input type="number" style="padding-left:0;" name="radio_21_22_amt" id="radio_21_22_amt" value="" min="0" max="50000000" step="1" onblur="javascript:select_radio_item_other_button(this, 'radio_21_22')">
</label>
</div>
Thanks all - I used a combination of your responses but this is working:
function select_radio_item_other_button(text_obj, radio_but)
{
var el = document.getElementById(radio_but);
if (text_obj.value != '') {
el.checked = true;
text_obj.className += " selected";
}
}
Brackets are a little off, perhaps something like this,
function select_radio_item_other_button(text_obj, radio_but) {
if (document.getElementById) {
el = document.getElementById(radio_but);
if (el.checked) {
return;
}
if (text_obj.value != '') {
el.checked = true;
text_obj.className += " selected";
}
}
}
Also not sure what if (document.getElementById) is supposed to return but what were you trying to accomplish here? It evaluates to true but that seems like an unintended purpose!
Hope this helps!
i have code that can be use for subtract and additional textbox values using javascript and it is working but problem is that javascript again and again executed function whenever onfocus textbox i want only one time javascript should be executed function?
javascript function again and again additional onMouseOver="return B(0);"
javascript function again and again subtraction onfocus="return C();"
javascript function again and again additional onfocus="return D();"
function getObj(objID){
return document.getElementById(objID);
}
function B(){
var advanceBox = document.getElementById('advance');
var originalValue = advanceBox.value;
advanceBox.onfocus = function() {
this.value = parseFloat(originalValue, 10) +
parseFloat(document.getElementById('recamt').value, 10);
return false;
};
}
function C() {
getObj("balance").value=parseFloat(getObj("total").value || 0)-
(parseFloat(getObj("advance").value || 0)) ;
getObj("balance").value=parseFloat(getObj("balance").value || 0)-
(parseFloat(getObj("discount").value)||0) ;
return false;
}
function D() {
getObj("total").value=parseFloat(getObj("total").value || 0)+
(parseFloat(getObj("openbal").value || 0)) ;
return false;
}
Opening Balance:<input class="input_field2"
type="text" name="openbal" id="openbal"><br />
Total:<input class="input_field2" type="text"
readonly name="total" id="total" value="5000"><br />
Advance:<input class="input_field2" type="text"
readonly name="advance" id="advance" value="500"
onMouseOver="return B(0);"><br />
Balance:<input class="input_field2" readonly type="text"
name="balance" id="balance" onfocus="return C();"><br />
Rem Amount:<input class="input_field2" type="text"
name="recamt" id="recamt"><br />
Discount: <input class="input_field2"
style="background-color:#FFF !important;"
type="text" name="discount" id="discount" >
You could have:
var executedAlready = false;
An inside functions B and C have:
if(executedAlready != true){ executedAlready = true; }
else { return; }
Or maybe you could detach the events instead? I guess there are a few different ways to do this.
What the other answers tell you that the "quickest" way to get results is to make your functions only execute once.
You can do that like this:
Make a flag (just a variable that knows if your function has been triggered already).
When executing your functions, first check on this flag.
Here's an example how to do it with function B():
(Note: I didn't change your function, don't wanna get into that now)
// setup fired as false
var hasBFired = false;
function B(){
// if B is true, we do nothing
if (hasBFired) {
return;
// else if it is not true, basically only the first time you call this, flip the flag and execute the rest of the code.
} else {
hasBFired = true;
}
var advanceBox = document.getElementById('advance');
var originalValue = advanceBox.value;
advanceBox.onfocus = function() {
this.value = parseFloat(originalValue, 10) +
parseFloat(document.getElementById('recamt').value, 10);
return false;
};
Now, repeat the same with C and D functions (setup two more flags).
This is not the best way - it's not good to setup global objects and stuff, but since you probably aren't getting any side library in, it will help you solve your issue for now. For long term solution, you should use an Event library (like YUI Event) and have it handle attaching and detaching actions to onfocus events for you.
you can use one or more flag(s) :
in the begenning of the page :
<script>
var flag = false;
</script>
and on your element:
<div .... onMouseOver="if(!flag) { flag = true; return B(0);}" > .... </div>
same for onFocus...
I know it is very simple.But Still it is not working.I am multiplying a input number with a fixed number,but is not showing the expected result.it always shows the Error message "Please enter some value" even i enter some integer e.g. 6.
This is Html Code.
<input type="text" class="cc" id="getdata" />
<div id="result"> <input type="text" id="show" /></div>
<input type="button" value="calculate" id="calculate" />
This is JQuery Code.
$(document).ready(function () {
$("#calculate").click(function () {
if ($("#input").val() != '' && $("#input").val() != undefined) {
$("#result").html("total value is::" + parseInt($("#input").val()) * 5);
}
else {
$("#result").html("Please enter some value");
}
});
});
Any help will be highly appreciated.
Can anyone tell me please how to concatenate all clicked values of different buttons in a textbox?I want to show previous and current clicked value of button in a textbox.
Thank you.
Do you not mean #getdata? Where is #input?
Replace ("#input") with ("#getdata") in your code.
Check out this fiddle.
$(document).ready(function () {
$("#calculate").click(function () {
if ($("#getdata").val() != '' && $("#getdata").val() != undefined) {
$("#result").html("total value is::" + parseInt($("#getdata").val()) * 5);
} else {
$("#result").html("Please enter some value");
}
});
});
You have no input whose id is "input". The jquery selector #somestring is looking for an element whose id is somestring.
Replace ("#input") by ("#getdata") in your code.
There is no field with the ID input in the HTML you posted, yet your jQuery is looking for one. Perhaps you meant $('#show')
With jQuery issues, ALWAYS suspect the selector before even wondering what else might be wrong. Confirm it actually finds the elements you think it does - never assume.
console.log($('#input').length); //0
if ($("#input").val() != '' && $("#input").val() != undefined) {
You dont have any field anywhere in your markup with the id input!
I think you intended all the instances of #input in that script to be #getdata, but you should also only read its value once into a variable and use that:
$("#calculate").click(function () {
var val = $('#getdata').val();
if (val != '' && val != undefined) {
$("#result").html("total value is::" + parseInt(val) * 5);
}
else {
$("#result").html("Please enter some value");
}
});
Live example: http://jsfiddle.net/82pf4/
$(document).ready(function () {
$("#calculate").click(function () {
if ($("#getdata").val() != '' && $("#getdata").val() != undefined) {
$("#result").html("total value is::" + parseInt($("#getdata").val()) * 5);
}
else {
$("#result").html("Please enter some value");
}
});
});
Checkout this Fiddle
I think that is what you want.
<input type="text" class="cc" id="getdata" />
<input type="button" value="calculate" id="calculate" />
<div id="result"></div>
<script>
$("#calculate").click(calculate);
$("#getdata").keypress(function(ev){
if(ev.keyCode == 13)
calculate();
});
function calculate()
{
var $getData = $("#getdata");
var $result= $("#result");
if ($getData .val() != '' && $getData .val() != undefined && !isNaN($getData .val()))
{
$result.append((parseInt($getData .val()) * 5) + "<p>");
}
else
{
$result.append("Please enter some value<p>");
}
$getData .val("").focus();
}
</script>
I want to add to this code a "window.onbeforeload" event to show a message that prevent the user from quitting the current page without adding the products to cart.
I have to show only when the quantity in > than 0 and with respecting the code below.
How can I do that ?
<form> <p><input class="qty"
type="text" maxlength="1" value="0" /></p>
<p><input class="qty" name="text"
type="text" value="0" /></p> <p><input
class="qty" name="text2" type="text"
/></p> </form>
<script type="text/javascript">
$(".qty").change(function(e) {
if(this.value != '3' && this.value != '6' && this.value != '9') {
this.value = 0;
alert('You can buy only 3, 6, or 9 pieces fromn this product');
} }); </script>
Thanks for help :)
Not sure why everyone is suggesting globals. This method requires no globals and no change() listener (which you may still need if you want that alert there). Based on MDC, assuming support for [].indexOf:
window.onbeforeunload = function (e) {
var e = e || window.event;
if (['3','6','9'].indexOf($(".qty").val())>=0) {
return;
}
else {
var msg = 'You can buy only 3, 6, or 9 pieces from this product';
// For IE and Firefox prior to version 4
if (e) {
e.returnValue = msg;
}
// For Safari
return msg;
}
};
With multiple inputs you will need to change the condition slightly:
var valid = true;
$('.qty').each(function(){ valid = valid && ['3','6','9'].indexOf($(this).val())>=0; });
if (valid) {
return;
}
else { ... }
You would need to set some "global" variable. GLobal does not necessarily mean global to the window, just enough it's global in your own namespace (which you hopefully got).
if(this.value != '3' && this.value != '6' && this.value != '9') {
NotifyTheUser = true;
}
else {
NotifyTheUser = false;
}
window.onbeforeunload = function() {
if( NotifyTheUser ) {
return 'Check your input.. foo bar yay!';
}
};
you can save the value in some global variable and then onbeforeunload look for that value, whether it's greater than 0 or not.
var valueContainer = 0;
$(".qty").change(function(e) {
valueContainer = this.value;
//rest of your code
});
window.onbeforeunload = function() {
if( valueContainer == 0) {
return 'Please Don't go away without selecting any product :(';
} };