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JavaScript user prompt 2d array lookup - Elf Name Generator

Started with what I thought was a simple idea for a class activity for our JavaScript unit, but falling foul best way to read a JavaScript 2D array based on a user input.
How can I get it to look up the users entry in the first index of the array and output the value in the second index? I need to tell it at some point which index to read and which to output, via similar syntax to [0][1] I imagine, but trial and error is getting me far.
Perhaps there is a better way??
Here is what I have so far, which just outputs the first array entry in its entirety - "A","Angelic"
var firstNames = [
["A","Angelic"],
["B","Blustery"],
........
["Y","Cheery"],
["Z","Dancy"]
];
var firstInitial = window.prompt("What is the first letter of your first name: ").toUpperCase();
let elfFirstName = firstNames.find(firstSearch);
function firstSearch(firstInitial) {
return firstInitial;
}
window.alert("Your Elf Name is " + elfFirstName);
</script>```
Thanks

You could take an object with the initials as keys.
const
firstNames = {
A: "Angelic",
B: "Blustery",
Y: "Cheery",
Z: "Dancy"
},
firstInitial = window.prompt("What is the first letter of your first name: ")[0].toUpperCase(),
elfFirstName = firstNames[firstInitial];
console.log("Your Elf Name is " + elfFirstName);

You do not use find right. It needs to look at the first index of your array that is passed in.
function firstSearch(item) {
return item[0] === firstInitial;
}
So
var firstNames = [
["A", "Angelic"],
["B", "Blustery"],
["Y", "Cheery"],
["Z", "Dancy"]
];
var firstInitial = window.prompt("What is the first letter of your first name: ").toUpperCase();
const elfFirstName = firstNames.find(firstSearch)[1];
function firstSearch(item) {
return item[0] === firstInitial;
}
window.alert("Your Elf Name is " + elfFirstName);
Better solution as I pointed out in the comments is using an array
var firstNames = {
A: "Angelic",
B: "Blustery",
Y: "Cheery",
Z: "Dancy"
};
var firstInitial = window.prompt("What is the first letter of your first name: ").toUpperCase();
const elfFirstName = firstNames[firstInitial];
window.alert("Your Elf Name is " + elfFirstName);

Discord.js: Pushing to array is combining strings

I am editing an embed message to update users that have "signed up" to a list by reacting. However, after my array length gets to 2, it begins combining the strings of the entire array before adding the new entry. Here is my code:
let newParticipant = getNickname(guildMembers) || user.tag;
//this line exists because "value" cannot be empty in an embed field
//so this removes the placeholder on the first entry
if (newEmbed.fields[2].value[0] === "0") {
newEmbed.fields[2].value = [
`${newEmbed.fields[2].value.length}. ${newParticipant}`,
];
} else {
let participants = [newEmbed.fields[2].value];
let newEntry = participants.length + 1 + ". " + newParticipant;
participants.push(newEntry);
newEmbed.fields[2] = { name: "Participants", value: participants };
console.log(newEmbed.fields[2].value);
}
However this is the output I'm getting after 3 reactions:
[ '1. Cardinal' ]
[ '1. Cardinal', '2. Cardinal' ]
[ '1. Cardinal\n2. Cardinal', '2. Cardinal' ]
Is this something native to discord? Is my logic bad? I've tried using a spread operator when bringing in the array and several other things...

this worked. thank you Worthy Alpaca. I still wish I knew what exactly was happening lol.
let participants = newEmbed.fields[2].value;
let num = participants.split("\n").length;
let newEntry = `\n${num + 1}. ${newParticipant}`;
participants += newEntry;
newEmbed.fields[2] = { name: "Participants", value: participants };
console.log(newEmbed.fields[2].value);

list of strings from array to variable name

I'm grabbing a list of elements ids thusly.
var menus = $(".menu").map(function(){
return this.id;
});
Which returns something like:
["lunch", "appetizers", "soup", "salads", "seafood", "noodles", "stir_fry", "curry", "kids", "steak", "dessert", "sides"]
For each item in the array I want to grab some JSON data.
$.each(menus,function(i) {
var list = menus[i],
meal = data.menu.list,
items = '<li><h3>' + meal.name + '</h3><p>' + meal.desc + '</p></li>';
$('#'+list+".menu").append(items);
});
Such that data.menu.list would be data.menu.lunch, data.menu.appetizers, etc.
The JSON is structured like so:
{
"menu": {
"lunch": [{
"name": "Kao PAdd",
"desc": "Fried rice with onions, green onions, snow peas, and egg / Chicken, vegetarian / Shrimp or tofu (Add $1)"
}
Any thoughts that don't involve eval()?
EDIT:
I when I do this:
$.each(data.menu,function(i) {
console.log(data.menu[i].key);
});
the console gives me:
Object {lunch: Array(14), appetizer: Array(11)}
All I really want is to access those arrays.
console.log(data.menu[i].name)
gives me a pair of undefineds.

That’s a brilliant question, Sir!
No matter how you retrieve your menus, strToVar() will do the task.
This code converts strings from array to variable names:
Solution:
var strToVar = (str,val) => this[str] = val;
Example:
var menus = ["lunch", "appetizers", "soup", "salads", "seafood", "noodles",
"stir_fry", "curry", "kids", "steak", "dessert", "sides"];
menus.forEach(strToVar);
prompt("[lunch, appetizers, soup, salads, seafood, noodles, " +
"stir_fry, curry, kids, steak, dessert, sides]",
[lunch, appetizers, soup, salads, seafood, noodles,
stir_fry, curry, kids, steak, dessert, sides]);
Give me all your points.

If you're looking for parsing JSON string to object here you go:
var jsonString = '{"data":{"item":{"id":1,"value":"foo"}}}';
var jsonObj = JSON.parse(jsonString);
console.log(jsonObj.data.item.value);

The problem was, I didn't understand what I really wanted to do. I asked the wrong question (although it's an interesting one, so I'll leave it up).
I thought I needed to generate my variable list from the HTML ids, but that was a mistake. What I needed was simply another for loop (or jQuery each());
$.each(data.menu, function(i) {
var list = data.menu[i],
menus = [];
$.each(list, function(x) {
var items = '<li><h3>' + list[x].name + '</h3><p>' + list[x].desc + '</p></li>';
menus.push(items)
});
$('#' + i).append(menus);
});

Your $.each function should be:
$.each(menus, function(i, list) { // the second parameter is list so we don't need menus[i]
var meal = data.menu[list], // use of bracket notation
items = '<li><h3>' + meal.name + '</h3><p>' + meal.desc + '</p></li>';
$('#' + list).append(items);
// ^^^ no need for the ".menu" as IDs alone are sufficient (assuming you have unique IDs, otherwise you have a problem)
});
Docs on MDN for bracket notation.

As per my understanding you want to achieve something like this :
var menus = ["lunch", "appetizers", "soup", "salads"];
var menuList = [
{
"name":"lunch",
"description":"description1"
},
{
"name":"appetizers",
"description":"description2"
},
{
"name":"soup",
"description":"description3"
},
{
"name":"salads",
"description":"description4"
}
]
var menu = {};
for(var i in menus) {
menu[menus[i]] = [{
"name": menuList[i].name,
"desc": menuList[i].description
}];
}
console.log(menu);

Compare list of duplicate emails using lodash underscore

I will try to explain what I need to do, why it is not so simple to explain.
I have 4 email lists, and in them there are duplicate items among them, need to extract these emails, for example:
list 1:
email1, email2, email4, email5
list 2:
email2, email3, email5, email6
list 3:
email1, email2, email7, email8
list 4:
email2, email4, email6, email7
I need this:
Result:
email1 (list1, list3)
email2 (list1, list2, list3, list4)
email3 (list2)
....
I'm trying to do this with javascript, because in fact these emails are in an excel ..
JSbin:
http://jsbin.com/zerexuviya/edit?html,js,console,output

Here is the solution I've just wrote using only Underscore.js: https://jsfiddle.net/alienpavlov/b0zaz5Lw/
var all = {
"list1": [
"email1",
"email2",
"email3",
"email4",
"email5",
"email6"
],
"list2": [
"email2",
"email3",
"email6",
"email7"
],
"list3": [
"email1",
"email3",
"email4",
"email5",
"email6"
],
"list4": [
"email1",
"email3",
"email5",
"email6"
]
};
var listOfAllEmails = _.union.apply(undefined, _.values(all));
_.each(listOfAllEmails, function(email, i) {
var result = [];
_.each(all, function(list, j) {
if (_.indexOf(list, email) > -1) {
result.push(j);
}
});
if (result.length > 1) {
//console.log(email, "=>", result);
var div = document.getElementById("result")
div.innerHTML = div.innerHTML + email + " (" + result + ")<br>";
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>
<div id="result"></div>
It was all about sorting arrays. If you have any questions feel free to ask in comments.

Populate a list (not HTML) from JSON

I am trying to use wordcloud2.js to generate some word clouds. It works fine using the example given:
var options =
{
list : [
["Pear", "9"],
["Grape", "3"],
["Pineapple", "8"],
["Apple", "5"]
],
gridSize: Math.round(16 * document.getElementById('canvas_cloud').offsetWidth / 1024),
weightFactor: function (size) {
return Math.pow(size, 1.9) * document.getElementById('canvas_cloud').offsetWidth / 1024;
}
}
WordCloud(document.getElementById('canvas_cloud'), options);
However, I am struggling with populating "list :" with the data from a JSON file with the following structure:
[
{
"wordCloud": "Manchester",
"Freq": 2321
},
{
"wordCloud": "Munich",
"Freq": 566
},
{
...
},
{
"wordCloud": "Madrid",
"Freq": 6
}
]
I know it is because my limited knowledges on pushing values to arrays. So far, my tries have been:
$.getJSON('json/wordCloudGWT-' + site + '.json', function (data) {
var wordCloudGWT = [];
for (var i=0;i<100;i++) {
wordCloudGWT.push([data[i].wordCloud, data[i].Freq]);
};
console.log(wordCloudGWT);
var options =
{
list : wordCloudGWT,
gridSize: Math.round(16 * document.getElementById('canvas_cloud').offsetWidth / 1024),
weightFactor: function (size) {
return Math.pow(size, 1.9) * document.getElementById('canvas_cloud').offsetWidth / 1024;
}
}
WordCloud(document.getElementById('canvas_cloud'), options);
console.log(wordCloudGWT); shows an array with 100 (objects?) with a length of 2 each, but the wordcloud doesn't show. I see in my browser's console an error which I assume is because wordcloud2.js is not interpreting list : wordCloudGWT as I (erroneously) think it should be.
If I bruteforce the creation of the list this way
list : [
[data[0].wordCloud, "9"],
[data[1].wordCloud, "3"],
[data[2].wordCloud, "8"],
[data[3].wordCloud, "5"]
],
the words are shown correctly, but this approach has two problems:
Real frequency of words (word's size) is not considered
There is surelly more elegant ways to generate the list as manually adding 100 lines of code
For the first point, I figured that I could solve the problem by also manually editing the list this way:
list : [
[data[0].wordCloud, data[0].Freq],
[data[1].wordCloud, data[1].Freq],
[data[2].wordCloud, data[2].Freq],
[data[3].wordCloud, data[3].Freq]
],
However, doing that ends with the same JS error from my first attempt.
Any hint that can help me to bypass my difficulties?

You can use Array.map to format the data:
var formattedList = responseData.map(function(item) {
return [item.wordCloud, item.Freq]
});
Demo: http://jsfiddle.net/64v75enq/

It seems like the wordcloud2.js library expects the frequency value to be a string, and that is not the case of your json data. So improving on your own example code; add a toString() at the end of the Freq variable when pushing the values. Like this:
list : [
[data[0].wordCloud, data[0].Freq.toString()],
[data[1].wordCloud, data[1].Freq.toString()],
...
]