Javascript function error.

and180y

Hi Richard, thanks for replying. :) I noticed that when I was searching for answers to my initial problem, nothing is ever easy it seems. The function I was trying to create would be used elsewhere but as yet I still can't get it to return a value.

and180y

Thanks for replying Richard. :) I have made the change you gave me but still not getting it to return a value. I'm still searching for my "lightbulb moment" with these functions.

Lost User

Try adding a return statement (with an associated value) at the end of the function.

and180y

Thanks Richard, not sure what I have done wrong here as still not giving a value for hours open.

$(function(){
$("#closing-time").keyup(function(){
var openingTime = $("#openingTime").val();
var closingTime = $("#closingTime").val();
$("hoursOpen").html(closingTime-openingTime);
return hoursOpen.html;

Estys

$("hoursOpen")

should probably be

$("#hoursOpen")

If you can read this, you don't have WingDings installed

Lost User

You have not declared hoursOpen anywhere. And what about the previous statement, does that not set the value in the html? If so why are you trying to return a value?

and180y

Hi Richard, thanks. I thought I had cobbled something together that would work from the lessons I saw and looking at other code. As I say there must be a lighbulb moment I am missing. :)

and180y

Estys Thanks, I think from other replies I am on the wrong track. :(

Lost User

See JavaScript Tutorial[^] and jQuery Tutorial[^] for more help.

Richard Deeming

Try something like this:

$(function(){
// Convert either "HH.mm" or "HH:mm" to the number of minutes since midnight
var parseMinutes = function(value){
var parts = value.split(/[.:]/g);
switch (parts.length) {
case 1: {
return parseFloat(parts[0]) * 60;
}
case 2: {
var hours = parseFloat(parts[0]);
var minutes = parseFloat(parts[1]);
return (hours * 60) + minutes;
}
default: {
return 0;
}
}
};

// Format a number of minutes as "HH:mm"
var formatMinutes = function(minutes){
    var hours = Math.floor(minutes / 60);
    minutes %= 60;
    
    return hours.toString().padStart(2, '0') + ':' + minutes.toString().padStart(2, '0');
};

var updateHoursOpen = function(){
    var openingTime = $("#opening-time").val();
    var closingTime = $("#closing-time").val();
    
    var openingMinutes = parseMinutes(openingTime);
    var closingMinutes = parseMinutes(closingTime);
    var minutesOpen = closingMinutes - openingMinutes;
    
    // If closing is before opening, the time spans midnight. Add a day's worth of minutes:
    if (minutesOpen < 0) {
        minutesOpen += 1440;
    }
    
    var hoursOpen = formatMinutes(minutesOpen);
    $("#hoursOpen").val(hoursOpen);
    return hoursOpen;
};

// Update the hours when either input is changed:
$("#opening-time, #closing-time").keyup(updateHoursOpen);

});

Demo[^] NB: padStart doesn't work in Internet Explorer. But since even Microsoft agree that IE isn't a browser[^], it's usually safe to ignore it these days.

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

and180y

Richard, thankyou so much for that, weirdly I'm still not getting a value for hours open. Sticking my head in the oven is starting to look appealing. :laugh:

and180y

Richard, my apologies. It has oft been said "there are none so blind as them that cannot see" Your code does work, I just wasn't looking at it correctly. :doh: :doh: Is there a way I can make it work for each day from the same code or would it need that code for each day? Thanks for your help so far. :)

Richard Deeming

I'm not sure what you mean by "each day"? Do you mean you have multiple sets of inputs for opening time, closing time, and hours? You can't use the same ID for multiple elements in the same HTML document. You'll need to find a different way of identifying the elements, and linking the three <input> elements for a given day together. For example, you could use the class attribute:

<div class="opening-day">
<p>Monday</p>
<p>
<label>
Opening:
<input type='text' class='opening-time' value='00:00'>
</label>
</p>
<p>
<label>
Closing:
<input type='text' class='closing-time' value='00:00'>
</label>
</p>
<p>
Result:
<input type='text' class='hours-open' value='00:00' readonly>
</p>
</div>

var updateHoursOpen = function($div){
var openingTime = $div.find(".opening-time").val();
var closingTime = $div.find(".closing-time").val();

var openingMinutes = parseMinutes(openingTime);
var closingMinutes = parseMinutes(closingTime);
var minutesOpen = closingMinutes - openingMinutes;
if (minutesOpen < 0) {
    minutesOpen += 1440;
}

var hoursOpen = formatMinutes(minutesOpen);
$div.find(".hours-open").val(hoursOpen);
return hoursOpen;

};

$(".opening-day").on("keyup", ".openingtime, .closing-time", function(){
var $div = $(this).closest(".opening-day");
updateHoursOpen($div);
});

Demo[^] .find() | jQuery API Documentation[^] .closest() | jQuery API Documentation[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

and180y

Hi Richard, thanks so much. Yes basically the page has all 7 days, a check box if open that day and input boxes for opening and closing hours and the hours open. I will use the code above. thankyou.

DerekT P

Saw this thread, and suddenly had awful deja vu back to 17th Feb 1999[^] (This is one of my all-time favourite Dilberts, simply because I see it in real life so often!)

jkirkerx

I know I'm late on this, but 0 - 0 is 0 opening time is 0 or 12 midnight closing time is 0 or 12 midnight so you get 0

If it ain't broke don't fix it Discover my world at jkirkerx.com

and180y

I was just glad the code worked. :) :)

jkirkerx

:) I wrote a similar function for showing that my business is open, based on open and closed hours in TypeScript. It drove me nuts, was always off by an hour, Daylight savings. I'll get back to it soon, now that I have more experience in TypeScript. :(

setStoreHours(): void {
const date = new Date();
const newDate = new Date(date.getTime() + date.getTimezoneOffset() * 60 * 1000);
const offset = date.getTimezoneOffset() / 60;
this.hourOfDay = date.getHours();
this.dayOfWeek = date.getDay();
switch (this.dayOfWeek) {
case 0:
// Sunday
this.storeStatus = "Closed";
break;
case 1:
// Monday
if (this.hourOfDay > 8 && this.hourOfDay < 17) {
this.storeStatus = "Open";
}
break;
case 2:
// Tuesday
if (this.hourOfDay > 8 && this.hourOfDay < 17) {
this.storeStatus = "Open";
}
break;
case 3:
// Wednesday
if (this.hourOfDay > 8 && this.hourOfDay < 17) {
this.storeStatus = "Open";
}
break;
case 4:
// Thursday
if (this.hourOfDay > 8 && this.hourOfDay < 17) {
this.storeStatus = "Open";
}
break;
case 5:
// Friday
if (this.hourOfDay > 8 && this.hourOfDay < 15) {
this.storeStatus = "Open";
}
break;
case 6:
// Saturday
this.storeStatus = "Closed";
break;
default:
this.storeStatus = "Closed";
}
}

If it ain't broke don't fix it Discover my world at jkirkerx.com

and180y

Where's the best place to learn how to write functions and class functions. I've ran through the courses Richard suggested above but none seem to be taking me where I need to be or am I trying to walk before I can run? :-) To me this should run but it's not returning a value, (or I'm not grasping how to get it to do so)

$(function(){
$("#current-charge").keyup(function(){
var time = $("#time-allowed").val();
var current = $("#current-charge").val();
$("breakeven").html(time * current);
})
})

jkirkerx

That's JQuery like syntax. IMO, Don't waste your time learning JQuery, I've been there and done that already. JQuery is obsolete now, because modern browsers support modern JavaScript. JQuery adds 3 Lbs to your first page download, and is very heavy in weight, in exchange to write shorthand JavaScript. The reason your not absorbing or moving faster with knowledge is because your looking at shorthand JavaScript/JQuery examples, and trying to understand and copy them. These are very advanced writing skills. You should start with entry level skill writing, and when you get that down, move to shorthand. I would of wrote it like this, for a beginner example. ES6 Use HTML to bind the event to the button, and run calcTime(). Use camel case to label things eg. calcTime vs CalcTime vs calc-time let has replaced var use const instead of var or let to when something that is constant. Try not to make a lot of const, see how I did it in one line ES6 Example

Calculate

function calcTime() {

// Make references to input elements
const time = document.getElementById("currentCharge"),
current = document.getElementById("timeAllowed"),
breakEven = document.getElementById("breakEven");

// Get the element values, convert to number/float
// By default, values are strings, and don't do math well.
let t = parseFloat(time.value);
let c = parseFloat(current.value);

// Perform the equation
let bE = t * c;

// Output the equation
breakEven.innerHTML = bE.toString();

}

JavaScript comes in many flavors now. I think you want ECMAScript 6, ES6, ECMAScript 2015 From there, you can branch out to TypeScript, Node, etc. I don't know of a good learning course, but you need to stick to one version in order to learn. And when searching for help on the internet, find examples in ES6; learn to identity ES6 examples, and then code and test.

If it ain't broke don't fix it Discover my world at jkirkerx.com