JavaScript substraction function not working properly - javascript

I made a simple html and JS click counter website but I cant get the minus function to work.
Heres my code:
<!DOCTYPE html>
<html>
<head>
<title>
Tally Counter
</title>
<Link rel='stylesheet' href='style.css'>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>></script>
<script type="text/javascript" src="//code.jquery.com/jquery-1.10.2.min.js"></script>
<script type="text/javascript" src="http://s3.amazonaws.com/codecademy-content/courses/hour-of-code/js/alphabet.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
var add = (function(){
var counter = 0;
return function (){return counter+=1;}
})();
function addCount(){
document.getElementById("carrier").innerHTML = add();
}
var minus = (function(){
return function (){return counter-=1;}
})();
function minusCount(){
document.getElementById("carrier").innerHTML = minus();
};
</script>
</head>
<body>
<h1>
Counter
</h1>
<p id='carrier'> 0 </p>
<button onclick="addCount()">Add count</button>
<button onclick="minusCount()">Lower count</button>
</body>
</html>
Only the lower count button doesn't work. Can someone help and tell me if I am missing somethnig?

You need to define counter outside your add method.
[edit] You defined your counter variable inside a function, so it can only be reached from inside said function. By moving it outside, every function can reach (and modify) the variable.
<!DOCTYPE html>
<html>
<head>
<title>
Tally Counter
</title>
<Link rel='stylesheet' href='style.css'>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>></script>
<script type="text/javascript" src="//code.jquery.com/jquery-1.10.2.min.js"></script>
<script type="text/javascript" src="http://s3.amazonaws.com/codecademy-content/courses/hour-of-code/js/alphabet.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
var counter = 0; // here
var add = (function(){
// var counter = 0; // not here
return function (){return counter+=1;}
})();
function addCount(){
document.getElementById("carrier").innerHTML = add();
}
var minus = (function(){
return function (){return counter-=1;}
})();
function minusCount(){
document.getElementById("carrier").innerHTML = minus();
};
</script>
</head>
<body>
<h1>
Counter
</h1>
<p id='carrier'> 0 </p>
<button onclick="addCount()">Add count</button>
<button onclick="minusCount()">Lower count</button>
</body>
</html>

Related

Countdown clicker - JS

I'm totally lost as to where to begin here, how would I create a countdown button so that each time my button is clicked, it prints out the global variable and reduce it by 1 in the innerHTML and when it hits 0 it says BOOM?
I know I have to declare the variable outside but not sure what to do afterwards
JS:
var i = 20
function myFunction()
{
i = i--; // the value of i starting at 20
}
HTML:
<!DOCTYPE html>
<html lang="en">
<head>
<!-- link to external JS file. Note that <script> has an
end </script> tag -->
<meta charset="utf-8">
<title> Task 6 </title>
<link href="style.css" type="text/css" rel="stylesheet">
<script src="task6.js" type="text/javascript"></script>
</head>
<body>
<!-- Create a paragraph with id mydata -->
<div id="box">
<p id="mydata"> Count Down </p>
<p> <button onclick="myFunction();"> Click </button></p>
</div>
</body>
</html>
I tryed this code and works fine
var i = 20;
function myFunction() {
myData = document.getElementById("mydata");
i = i - 1;
myData.textContent = i;
if(i <= 0) {//with <=0 the user if click again,after zero he sees only BOOM
myData.textContent = "BOOM!"
}
}
html code
<!DOCTYPE html>
<html lang="en">
<head>
<!-- link to external JS file. Note that <script> has an
end </script> tag -->
<meta charset="utf-8">
<title> Task 6 </title>
<link href="style.css" type="text/css" rel="stylesheet">
<script src="task6.js" type="text/javascript"></script>
</head>
<body>
<!-- Create a paragraph with id mydata -->
<div id="box">
<p id="mydata"> Count Down </p>
<p> <button onclick="myFunction();"> Click </button></p>
</div>
<!DOCTYPE html>
<html lang="en">
<head>
<!-- link to external JS file. Note that <script> has an
end </script> tag -->
<meta charset="utf-8">
<title> Task 6 </title>
<link href="style.css" type="text/css" rel="stylesheet">
<script type="text/javascript">
var i = 20;
function myFunction() {
var myData = document.getElementById("mydata");
i = i - 1;
myData.textContent = i;
if(i <= 0) {
myData.textContent = "BOOM!"
}
}
</script>
</head>
<body>
<!-- Create a paragraph with id mydata -->
<div id="box">
<p id="mydata"> Count Down </p>
<p> <button onclick="myFunction();"> Click </button></p>
</div>
</body>
</html>
It's good practice to not inline JS in the HTML so I'll provide an extra example to show how to separate it out using a couple of DOM selection methods:
let count = 20;
// grab the element with the mydata id
const mydata = document.getElementById('mydata');
// grab the button and attach an click event listener to it -
// when the button is clicked the `handleClick` function is called
const button = document.querySelector('button');
button.addEventListener('click', handleClick, false);
function handleClick() {
if (count === 0) {
mydata.textContent = 'Boom';
} else {
mydata.textContent = count;
}
count--;
}
<body>
<p id="mydata">Countdown</p>
<button>Click</button>
<script src="task6.js" type="text/javascript"></script>
</body>
Reference
getElementById
querySelector
addEventListener
I'll assume you want to show the variable output and the BOOM at the <p id="mydata"> Count Down </p>, if I am mistaken correct me. So, something like this:
let i = 20;
const myData = document.querySelector("#mydata");
function myFunction() {
i = i - 1;
myData.textContent = i;
if(i === 0) {
myData.textContent = "BOOM!"
}
}
You almost got it whole,only missed the textContent and if part. If this is what you wanted to achieve. If this isn't what you were looking for, hit me up so I can correct it. Cheers :)
You need some way of displaying the number inside of your variable. One of the simplist ways to do this would be to set text to your paragraph tag using getElementById() and inner HTML. For example, after running your deincrement, on the next line you would do something like...
function myFunction()
{
i = i--; // the value of i starting at 20
document.getElementById("mydata").innerHTML = i;
}
This code simply grabs your "mydata" paragraph from the DOM and injects the number into the tag as html.

moment-countdown js library giving me a weird variable assignment?

The library I am using: https://github.com/icambron/moment-countdown
My code:
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
<!-- https://github.com/icambron/moment-countdown -->
<script src="moment.min.js"></script>
<script src="countdown.min.js"></script>
<script src="moment-countdown.min.js"></script>
</head>
<body>
<input type="datetime-local" id="timeInputHTML" onchange="mainfunc()>
<p id="pel"></p>
<script>
function mainfunc() {
timeVar = document.getElementById("timeInputHTML").value;
// var timeInputVar = moment("2045-01-01 00:00:00").countdown().toString();
var timeInputVar = moment(timeVar).countdown().toString();
document.getElementById("pel").innerHTML = timeInputVar;
}
// Run above function every 1 second
setInterval(mainfunc, 1000);
</script>
</body>
</html>
The question: How do I make the variable timeVar when it obtains its values from timeInputHTML in the HTML code, not contain contain a T in the middle like so: "2018-05-05T14:30" I believe this is what is wrong with my code and is causing the Uncaught TypeError if it is not the issue then please can you explain to me what is please?
The image / screenshot:
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
<!-- https://github.com/icambron/moment-countdown -->
<script src="moment.min.js"></script>
<script src="countdown.min.js"></script>
<script src="moment-countdown.min.js"></script>
</head>
<body>
<input type="datetime-local" id="timeInputHTML" onchange="mainfunc()">
<p id="pel"></p>
<script>
function mainfunc() {
timeVar = document.getElementById("timeInputHTML").value;
// var timeInputVar = moment("2045-01-01 00:00:00").countdown().toString();
var timeInputVar = moment(timeVar).countdown().toString();
document.getElementById("pel").innerHTML = timeInputVar;
}
// Run above function every 1 second
setInterval(mainfunc, 1000);
</script>
</body>
</html>
your are missing " this in input function it should be like this
<input type="datetime-local" id="timeInputHTML" onchange="mainfunc()">

Push value to html and grab again from JS

I want to assign a value to hidden input then grab that value from next section of javascript using input id. So it will alert the value as per hidden input value which assigned from the first section of javascript. However, it looks not useful this is important for my current task. I have to push value to HTML then get it back again in javascript variable. Let me know if you have any solution.
<!DOCTYPE html>
<html>
<head>
<title>Just test</title>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jszip/2.5.0/jszip.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/pdfmake/0.1.18/pdfmake.min.js"></script>
</head>
<body>
<script>
var myVal = "some string";
$("#foo").val(myVal);
</script>
<input type="hidden" name="foo" id="foo" value="">
<script>
var doo = "";
doo = $(this).find("#foo").val();
if (doo != "") {
alert(doo);
}else{
alert("doo is null");
}
</script>
</body>
</html>
You can use $(document).ready() method which waits until all DOM elements are rendered. Then executes the JS code. You can read more about it here
<!DOCTYPE html>
<html>
<head>
<title>Just test</title>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jszip/2.5.0/jszip.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/pdfmake/0.1.18/pdfmake.min.js"></script>
</head>
<body>
<script>
$(document).ready(function(){
var myVal = "some string";
$("#foo").val(myVal);
});
</script>
<input type="hidden" name="foo" id="foo" value="">
<script>
$(document).ready(function(){
var doo = "";
doo = $(this).find("#foo").val();
if (doo != "") {
alert(doo);
}else{
alert("doo is null");
}
});
</script>
</body>
</html>
Using HTMLFormControlsCollection of the Web API allows us to reference any and all form elements very easily:
Example
/* Find the first form of a page without knowing it's .class or #id */
// HTMLFormControlsCollection // Common way
var form = document.forms[0]; var form = document.getElementsByTagName('form')[0];
Demo
<!DOCTYPE html>
<html>
<head>
<title>Just test</title>
</head>
<body>
<form id='A'>
<input id="X" name="X">
<output id='Y' name='Y'></output>
<input id='Z' name='Z' type='hidden'>
</form>
<script>
var F = document.forms.A;
F.oninput = function() {
var X = F.X.value;
var Y = F.Y;
var Z = F.Z;
Y.value = X;
Z.value = X;
}
</script>
</body>
</html>

Getting a value from a color picker and returning it

I want to know how you would go about getting a value from a color picker and returning it to a js script
Here is the HTML Code
<!DOCTYPE html>
<script type="text/javascript" src="Scripts/jquery-3.1.1.js"></script>
<script type="text/javascript" src="js/bootstrap-colorpicker.js"></script>
<link rel='stylesheet' href='css/bootstrap-colorpicker.css' />
<script type="text/javascript" src="js/bootstrap-colorpicker.min.js"></script>
<link rel='stylesheet' href='css/bootstrap-colorpicker.min.css' />
<html lang="en" xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="utf-8" />
</head>
<body>
<p> test test test</p>
<div id="cp2" class="input-group colorpicker-component">
<input type="text" value="#00AABB" class="form-control" />
<span class="input-group-addon"><i></i></span>
</div>
<script>
$(function () {
$('#cp2').colorpicker({
color: '#AA3399',
format: 'rgb'
})
});
</script>
</body>
</html>
<script>document.getElementById("cp2").value = function () {
return rgb;
}
</script>
`
I am looking to return the value of the color picker which is in RGB format to a js script so that I will to able to assign vars like this
var 1 = rgb[1]
var 2 = rgb[2]
var 3 = rgb[3]
`
If you decide to help me I will be thankful and you could please explain so I can learn from it.
Check javascript function:
<script>
(function() {
var rgb = document.getElementById("cp2").value ;
return rgb;
})();
</script>

How to include a JavaScript object in a separate file

I'm trying to include a separate .js file so I can pull in a class I created but it doesn't work, can someone tell me why?
playercharacter.js
function PlayerCharacter() {
this.x = 0;
this.y = 0;
this.dx = 5;
this.dy = 5;
}
PlayerCharacter.prototype.sayHello = function()
{
alert ('hello');
};
index.html
<html>
<head>
<script src="js/playercharacter.js" type="text/javascript" ></script>
</head>
<body>
<script type="text/javascript" >
var player = new PlayerCharacter();
player.sayHello();
</script>
</body>
</html>
You forgot wrap your JS-code into the <script> tags
<html>
<head>
<script src="js/playercharacter.js" type="text/javascript" ></script>
</head>
<body>
<script type="text/javascript" >
var player = new PlayerCharacter();
player.sayHello();
</script>
</body>
</html>
Your JavaScript code is not in a script tag.
<script>
var player = new PlayerCharacter();
player.sayHello();
</script>
You need to surround the code in the body with a <script> tag.

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