Develop Reference

Pushing attribute value to two different arrays based on radio options selected

In short, if a user selects yes to a radio option, I'm trying to obtain the data-name attribute from that input and push it to an array called accepted_array.
If a user selects no, then store data-name to declined_array.
Here is a visual to the markup:
<div class="guest__options-group">
<input id="attending-yes-0" type="radio" name="attendance-0" value="yes" data-name="John" required />
<label for="attending-yes-0">Yes</label>
</div>
<div class="guest__options-group">
<input id="attending-no-0" type="radio" name="attendance-0" value="no" data-name="John" required />
<label for="attending-no-0">No</label>
</div>
<!-- options for Alex -->
<div class="guest__options-group">
<input id="attending-yes-1" type="radio" name="attendance-1" value="yes" data-name="Alex" required />
<label for="attending-yes-1">Yes</label>
</div>
<div class="guest__options-group">
<input id="attending-no-1" type="radio" name="attendance-1" value="no" data-name="Alex" required />
<label for="attending-no-1">No</label>
</div>
Here are 2 approaches I've experimented with:
First approache.
(function ($) {
$( ".guest__attendance-input" ).each(function(index) {
$(this).on("click", function(){
var $this = $(this);
var checkedVal = $this.val();
var accepted_array = [];
var declined_array = [];
if( checkedVal == "yes" ) {
var name = $this.data("name");
accepted_array.push(name);
} else {
declined_array.push(name);
}
console.log("accepted " + accepted_array.join(","));
console.log("declined " + accepted_array.join(","));
});
});
}) (jQuery);
This only executes for the selected user and adds the name to both arrays.
Second approache.
(function ($) {
$( ".guest__attendance-input" ).each(function(index) {
$(this).on("click", function(){
var $this = $(this);
var data = [];
var checked = $this.is(':checked');
var name = $this.attr('data-name');
if (checked) {
if (!data[name]) {
data[name] = []
}
data[name].push($this.val())
}
console.log(data);
});
});
}) (jQuery);
Which only adds the user to a single array.
If both select yes, I need both names in the accepted_array. If someone selects yes initially and then selects no I need to remove them from the accepted_array and vice versa.

You can use splice with inArray to remove value from array if someone selects yes initially and then selects no and vice versa.
Example:
var accepted_array = [];
var declined_array = [];
$('.guest__options-group > input[type=radio]').on('change', function() {
var $this = $(this);
var name = $this.data("name");
var checkedVal = $this.val();
var name = $this.data("name");
if (checkedVal == "yes") {
accepted_array.push(name);
declined_array.splice($.inArray(name, declined_array), 1);
} else {
declined_array.push(name);
accepted_array.splice($.inArray(name, accepted_array), 1);
}
console.log("accepted " + accepted_array.join(","));
console.log("declined " + declined_array.join(","));
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<!-- options for John -->
<div class="guest__options-group">
<input id="attending-yes-0" type="radio" name="attendance-0" value="yes" data-name="John" required />
<label for="attending-yes-0">Yes</label>
</div>
<div class="guest__options-group">
<input id="attending-no-0" type="radio" name="attendance-0" value="no" data-name="John" required />
<label for="attending-no-0">No</label>
</div>
<!-- options for Alex -->
<div class="guest__options-group">
<input id="attending-yes-1" type="radio" name="attendance-1" value="yes" data-name="Alex" required />
<label for="attending-yes-1">Yes</label>
</div>
<div class="guest__options-group">
<input id="attending-no-1" type="radio" name="attendance-1" value="no" data-name="Alex" required />
<label for="attending-no-1">No</label>
</div>

JQuery/JS Input Iteration

I am getting incorrect results from my logic and I'm not sure why. Any recommendations would be highly appreciated.
I have dynamically created cards with 1-3 inputs per card. I am trying to iterate through the cards and collect the input values for each individual card but instead I keep getting the input values for all the cards for each iteration
html
<div class="card">
<input type="hidden" class="sample" value="A">
<input type="hidden" class="sample" value="B">
</div>
<div class="card">
<input type="hidden" class="sample" value="A">
</div>
js
arr = []
$('.card').each(function (i, obj) {
$('.sample').each (function (i, obj) {
val = $(this).val()
arr.push(val)
})
})
I was expecting arr[A, B] and arr[A]
but i get arr[A, B, A] and arr[A, B, A]

You are getting this result due to inner loop is executing for all samples div present into HTML.
Use $(obj).find('.sample') instead of $('.sample'). It will execute for sample div within card div.
var arr = []
$('.card').each(function (i, obj) {
var ele = [];
$(obj).find('.sample').each (function (i, obj) {
val = $(this).val()
ele.push(val)
})
arr.push(ele)
})
console.log(arr);
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="card">
<input type="hidden" class="sample" value="A">
<input type="hidden" class="sample" value="B">
</div>
<div class="card">
<input type="hidden" class="sample" value="A">
</div>

The result you are getting is expected.
There are many ways to achieve what you want: "I was expecting arr[A, B] and arr[A]"
But for me, I would go for adding more distinctions in your classes:
card-0, card-1, and so on should be coded by you
html
<div class="card-0 cards">
<input type="hidden" class="sample" value="A">
<input type="hidden" class="sample" value="B">
</div>
<div class="card-1 cards">
<input type="hidden" class="sample" value="A">
</div>
js
var mainArray = [];
var cardsCount = $('.cards').length;
for (var i1 = 0; i1 < cardsCount; i1++) {
var arr = [];
$(".card-" + i1 + " :input").each(
function() {
arr.push($(this).val());
}
);
mainArray.push(arr);
}
alert(mainArray[0]);
alert(mainArray[1]);

How can I produce an alert if three out of nine checkboxes are checked?

I have nine checkboxes linked to nine images and three of them use the name 'correct' using the code shown below.
<div class="nine">
<label for="correct1"><img class="picture1" src="picture1.jpg"/></label>
<input type="checkbox" class="chk" id="correct1" name="correct"/>
</div>
The remaining six are unnamed using the code shown below.
<div class="nine">
<label for="incorrect1"><img class="picture4" src="picture4.jpg"/></label>
<input type="checkbox" class="chk" id="incorrect4"/>
</div>
I currently have the following code to produce an alert if the three checkboxes with the name "correct" are checked but it isn't working.
<script>
var i, correct = document.getElementsByName('correct');
for (i = 0; i <= correct.length; i++) {
if (correct[i].checked) {
alert('correct');
return true;
}
}
alert('incorrect');
return false;
</script>
Can anyone help me with this?

Loop over all of the checkboxes, checking their state. Once this is done, create a variable "correct" and initialize it to true. Then go to each state in the variable and, if you find that its name isn't "correct" and it is checked or its name is "correct" and it isn't correct, set the variable to false. Then check if the variable is true and, if it is, display the alert.
View an example here: https://repl.it/GxsE/9

Using ES6:
const correctInputs = [...document.querySelectorAll('input[name="correct"]')];
const alertIfThree = () => {
const checkedCorrectInputs = correctInputs.filter(input => input.checked);
if (checkedCorrectInputs.length > 2) {
alert('Alert');
}
};
correctInputs.forEach(input => input.addEventListener('click', alertIfThree));
<input type="checkbox" name="correct"/>
<input type="checkbox" name="correct"/>
<input type="checkbox" name="correct"/>
<input type="checkbox" name="correct"/>
<input type="checkbox" name="correct"/>
document.querySelectorAll('input[name="correct"]') gets all inputs with name "correct".
[...CODE] is spread operator, it converts code from previous point to array.
correctInputs.forEach(input => input.addEventListener('click', alertIfThree)) adds click event listener to each of them. That event listener is function alertIfThree().
alertIfThree() filters out those input elements that are not checked and produces alert if there are more than 2 of them.
EDIT
In response to your comment:
// jshint esnext: true
const inputs = [...document.querySelectorAll('input[name="correct"], input[name="incorrect"]')];
const alertIfCorrect = () => {
const checkedInputs = inputs.filter(input => input.checked),
noIncorrectCheckedInputs = checkedInputs.find(input => input.name === 'incorrect') === undefined;
if (checkedInputs.length > 2 && noIncorrectCheckedInputs) {
alert('Alert');
}
};
inputs.forEach(input => input.addEventListener('click', alertIfCorrect));
<p>Correct:
<input type="checkbox" name="correct"/>
<input type="checkbox" name="correct"/>
<input type="checkbox" name="correct"/>
<input type="checkbox" name="correct"/>
<input type="checkbox" name="correct"/>
</p>
<p>Incorrect:
<input type="checkbox" name="incorrect"/>
<input type="checkbox" name="incorrect"/>
<input type="checkbox" name="incorrect"/>
</p>
const is ES6 constant. "The value of a constant cannot change through re-assignment, and it can't be redeclared".
[...CODE_HERE] is so called spread syntax. Here, it turns what it contains after ellipsis into an array. Other way to do it would be to use Array.from().
() => { and input => CODE_HERE are arrow functions. They are ES6's syntactic sugar for function declaration.
What stands before => are parameters. () stands for 0 parameters. If you wanted function that takes few parameters, those braces would need to have those few parameters inside them. For one parameter, parameter's name can replace braces altogether (like in second code in this bullet point).
What stands after => is either expression or group of statements. Statements are surrounded by curly brackets ({}). If you omit them, you are writing an expression that your function will return. For example input => input.checked is equivalent to function(input) { return input.checked; }.
filter() and find() are methods of array prototype. They respectively filter and search an array using condition defined in a function that is passed to them as a parameter. Read more by following those two links.
If you need something else explained, let me know. Those functions and structures here are pretty... fresh, so you can just not know them yet.

I put this in a JSfiddle and it works for me. I just wrapped your JS in a function and added an onclick event.
<div class="nine">
<label for="correct1"><img class="picture1" src="picture1.jpg"/></label>
<input type="checkbox" class="chk" id="correct1" name="correct"onclick="validate()"/>
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="picture4.jpg"/></label>
<input type="checkbox" class="chk" id="incorrect4" onclick="validate()"/>
</div>
<script type=text/javascript">
function validate()
{
var i, correct = document.getElementsByName('correct');
for (i = 0; i <= correct.length; i++) {
if (correct[i].checked) {
alert('correct');
return true;
}
}
alert('incorrect');
return false;
}
</script>

It will require some javascript. You will need o check the checkboxes each time one changes. So to start with you will need to check your checkboxes, assuming they have an assigned class of 'chk'. This can be done with a querySelector.
Each time a checkbox changes, the function 'check_checkboxes()' is called. This function will see for each checkbox with name='correct' if it is checked and then increment 'count'
var checkboxes = document.querySelectorAll(".chk");
var correct = document.querySelectorAll("[name=correct]");
function check_checkbox() {
var count = 0;
[].forEach.call(correct, function(item) {
if (item.checked) {
count++;
}
});
if (count >= 3) {
alert("count of 3 or more");
}
}
[].forEach.call(checkboxes, function(item) {
item.addEventListener("change", function() {
check_checkbox();
}, false);
});
<div class="nine">
<label for="correct1"><img class="picture1" src="http://placehold.it/40x40"/></label>
<input type="checkbox" class="chk" id="correct1" name="correct" />
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="http://placehold.it/40x40"/></label>
<input type="checkbox" class="chk" id="incorrect4" />
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="http://placehold.it/40x40"/></label>
<input type="checkbox" class="chk" id="incorrect4" name="correct" />
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="http://placehold.it/40x40"/></label>
<input type="checkbox" class="chk" id="incorrect4" />
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="http://placehold.it/40x40"/></label>
<input type="checkbox" class="chk" id="incorrect4" name="correct" />
</div>

Check the loop. Use for (i = 0; i < correct.length; i++) { instead for (i = 0; i <= correct.length; i++) {
var i, correct = document.getElementsByName('correct');
var correct_answers = [];
function validate(){
correct_answers = [];
for (i = 0; i < correct.length; i++) {
var element = correct[i].getAttribute("id");
var checked = correct[i].checked;
correct_answers.push({element,checked});
}
}
function show(){
document.getElementById('results').innerHTML ="";
for(var e=0;e<correct_answers.length;e++){
var box = document.createElement('div');
box.innerHTML = correct_answers[e].element+ " " + correct_answers[e].checked+ "<br>";
document.getElementById('results').appendChild(box);
}
}
<div class="nine">
<label for="correct1"><img class="picture1" src="picture1.jpg"/></label>
<input type="checkbox" onclick="validate()" class="chk" id="correct1" name="correct"/>
</div>
<div class="nine">
<label for="correct2"><img class="picture1" src="picture1.jpg"/></label>
<input type="checkbox" onclick="validate()" class="chk" id="correct2" name="correct"/>
</div>
<div class="nine">
<label for="correct3"><img class="picture1" src="picture1.jpg"/></label>
<input type="checkbox" onclick="validate()" class="chk" id="correct3" name="correct"/>
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="picture4.jpg"/></label>
<input type="checkbox" onclick="validate()" class="chk" id="incorrect4"/>
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="picture4.jpg"/></label>
<input type="checkbox" onclick="validate()" class="chk" id="incorrect5"/>
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="picture4.jpg"/></label>
<input type="checkbox" onclick="validate()" class="chk" id="incorrect6"/>
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="picture4.jpg"/></label>
<input type="checkbox" onclick="validate()" class="chk" id="incorrect7"/>
</div>
<div class="nine">
<label for="incorrect1"><img class="picture4" src="picture4.jpg"/></label>
<input type="checkbox" onclick="validate()" class="chk" id="incorrect8"/>
</div>
<button onclick="show();">show results</button>
<div id="results"></div>

Use document.querySelectorAll('input[name]=correct') in your code.

Checkbox arrays

Just wondering if anyone can help. I currently have code like this:
<section>
<span class="tags"></span>
<label for="shoes">Shoes</label>
<input type="checkbox" id="shoes">
<label for="jeans">Jeans</label>
<input type="checkbox" id="jeans">
<label for="tops">Tops</label>
<input type="checkbox" id="tops">
</section>
<section>
<span class="tags"></span>
<label for="monkey">monkey</label>
<input type="checkbox" id="monkey">
<label for="lion">lion</label>
<input type="checkbox" id="lion">
<label for="dog">dog</label>
<input type="checkbox" id="dog">
</section>
Each 'section' is dynamically produced. How do I go about inserting the value of each input into the span of each section when checked. I have been playing around with Arrays but stumbling due to each section being produced dynamically.
Can any of you help me out?

Better give each checkbox input a value, anyway, I'll use id instead.
// Listen to all checkboxes
$('section input[type="checkbox"]').click(function(e) {
var $this = $(e.target);
// Find the container of same group.
var $parent = $this.parent('section');
// Find all checked ones.
var checked = $parent.find('input[type="checkbox"]:checked');
// Map the value or id, to an array.
var result = $.map(checked, function(ele) {
return $(ele).attr('id');
});
// Get the result, use it whatever you want.
$parent.find('.tags').text(result.join(' '));
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<section>
<span class="tags"></span>
<label for="shoes">Shoes</label>
<input type="checkbox" id="shoes">
<label for="jeans">Jeans</label>
<input type="checkbox" id="jeans">
<label for="tops">Tops</label>
<input type="checkbox" id="tops">
</section>
<section>
<span class="tags"></span>
<label for="monkey">monkey</label>
<input type="checkbox" id="monkey">
<label for="lion">lion</label>
<input type="checkbox" id="lion">
<label for="dog">dog</label>
<input type="checkbox" id="dog">
</section>

Use this javascript:
<script type="text/javascript">
window.addEventListener("load",function(){
var sections = document.getElementsByTagName("section");
for(var i=0; i<sections.length; i++){
var n = 0;
sections[i].span = sections[i].getElementsByTagName("span")[0];
sections[i].checkboxes = [];
var inputs = sections[i].getElementsByTagName("input");
for(var c=0; c<inputs.length; c++){
if(inputs[c].type!="checkbox"){continue}
sections[i].checkboxes[n++]=inputs[c];
inputs[c].onchange=function(){this.parentNode.getValues();}
}
sections[i].getValues = function(){
var o=[], n=0;
for(var i=0; i<this.checkboxes.length; i++){if(this.checkboxes[i].checked){o[n++] = this.checkboxes[i].id;}}
this.span.innerHTML = o.join(", ");
};
}
},false);
</script>

How to make array of values of objects

<input name="hello">value1
<input name="hello">value2
<input name="hello">value3
<input name="hello">value4
var a = getElementsByName('hello')
Now, how do I create an array that contains (value1,value2,value3,value4)?
I thought of using makeArray, but it returns just the objects not the values.

You can iterate over them, or use map.
var items = Array.prototype.map.call(a, function(el){
return el.nextSibling.textContent;
});
demo
var items = [];
for (var i=0; i<a.length; i++) {
items.push(a[i].nextSibling.textContent);
}
demo

First of all your html should look like that:
<input name="hello1" value="value1" type="text" />
<input name="hello2" value="value2" type="text" />
<input name="hello3" value="value3" type="text" />
<input name="hello4" value="value4" type="text" />
I.e. if you are using text boxes your name attribute should be different. Otherwise you can't get the values. And of course the values are actually attributes. Here is a pure javascript code which could do what you want:
var inputs = document.querySelectorAll("input[type='text']");
var result = [];
for(var i=0; field=inputs[i]; i++) {
result.push(field.value);
}
alert(result);
And here is a jsfiddle demonstrating the example http://jsfiddle.net/krasimir/nbmjG/

You should do this like:
HTML:
<input type="text" id="hello1" value="value1">
<input type="text" id="hello2" value="value2">
<input type="text" id="hello3" value="value3">
<input type="text" id="hello4" value="value4">
JS:
alert('ready?');
var n = 4;
var arr = new Array(n);
for(var i = 0; i < n; i++) {
arr[i] = document.getElementById('hello' + (i+1)).value;
}
alert(arr);
DEMO

Your inputs have to be like so: Demo
<input name="hello" value="value1">
<input name="hello" value="value2">
<input name="hello" value="value3">
<input name="hello" value="value4">
Then following will return array of values:
var arr = Array.prototype.map.call(document.getElementsByName('hello'), function(elem){
return elem.value;
});

You need to use []
<input name="hello[]">value1</input>
<input name="hello[]">value2</input>
<input name="hello[]">value3</input>
<input name="hello[]">value4</input>