Develop Reference

How to access object with a randomly chosen name stored in a variable?

I've got 16 objects with names like: aBoard, bBoard, cBoard and so on,
eg. let aBoard = { currentValue: 0, valuesHistory: [], ID: "unitA", borderValues: [1, 0, 0, 1], free: true };
I have an array of corresponding names, randomly chose one of them and change it so it matches the name of one of the objects.
const BOARDARRAY = ["unitA", "unitB", "unitC", "unitD", "unitE", "unitF", "unitG", "unitH", "unitI", "unitJ", "unitK", "unitL", "unitM", "unitN", "unitO", "unitP"];
let randomizer = Math.floor(Math.random()*16);
currentBoardTile = BOARDARRAY[randomizer];
let temp = (currentBoardTile.charAt(currentBoardTile.length -1).toLowerCase());
JSObjectBoardUnit = (temp + "Board");
How to access the object using my JSObjectBoardUnit?
In other words, how to make JS "understand" that I want to treat JSObjectBoardUnit value (string) as a value of the object address?
Eg. Let's day JSObjectBoardUnit = aBoard;
Basically the outcome I want is: aBoard.key1 = JSObjectBoardUnit.key1.
I'd love to use the value stored in JSObjectBoardUnit to access the name of the predefined object aBoard.

I'm not sure to understand well your question but I think this 2 methode could maybe help you.
You can access attribute of a object with a string by using
const obj = {toto: 1};
const name = "toto";
console.log(obj["toto"]); // 1
console.log(obj[name]); // here we use variable and the result is 1
so you could store all yoyr object inside one and do this.
const allBoard = {
"aboard": null, // do not put null use your board
}
console.log(allBoard[(temp + "board")]); // display the temp + board attribute so if temps is equal to a then it will get the aboard
this is what you want, getting object from a string.
But I saw that the aboard also have an id attribute with "unitA"
Instead you could build an array of aboard, bboard ....
and use the Array.find() methode that will return the object that match the condition.
in your case
const myBoardArray = [{ currentValue: 0, valuesHistory: [], ID: "unitA", borderValues: [1, 0, 0, 1], free: true }, ....];
let randomizer = Math.floor(Math.random()*16);
currentBoardTile = BOARDARRAY[randomizer];
myBoardArray.find((board) => board.ID === currentBoardTile);

2 options
Put the boards in a list, and iterate over them with a for loop. In the for loop, use an if statement to see which Id matches the board you want.
let boards = [aBoard , bBoard, cBoard];
boards.forEach(board=> {
if (board.ID == currentBoardTile) {
//do something
}
});
Create a dictionary where the key is the board id and the respective object is the value. Use the board id to get the respective value.
var boards = {
"unitA" : boardA,
"unitB" : boardB,
....
};
currentBoardTile = BOARDARRAY[randomizer];
console.log(currentBoardTile + " : " + boards[currentBoardTile]);

Find a string within a jQuery array that has multiple elements per object

I've got an array of employee's and assigned to each employee are a few elements.
Sample of array below:
var employees = [
{"name":"Johhny Test","salary":"1","email":"abc#123.com"},
{"name":"Mike Milbury","salary":"10","email":"184895#hdsjhfs.com"}
];
I've got a means of gathering the employee's last name and I'm storing it in a variable. I'd like to be able to search for the indexOf the last name housed in this variable so that I know at which position within the array that match is made.
So for instance, this array could be 100 items in size. Ideally I want to know that someone with the last name of "johnson" is in position 50 of this array. That way, I can go in and get the salary and email associated with their record from position 50 in the array.
The code I've got so far is this:
var lname = "Test";
var lnameMatch = employees.indexOf(lname);
console.log(lnameMatch);
This isn't working though - my console is logging -1, suggesting that it doesn't exist in the array. Is there a way that I can specify a element of that array to search against?
Almost like employees(name).indexOf(lname) where it is searching against the name element?
Or am I going about this all wrong and there is perhaps an easier less messy way to accomplish this?

You can use .findIndex:
const employees = [
{"name":"Johhny Test","salary":"1","email":"abc#123.com"},
{"name":"Mike Milbury","salary":"10","email":"184895#hdsjhfs.com"}
];
const lastName = "Test";
const index = employees.findIndex(employee => {
const { name = '' } = employee;
const nameParts = name.split(' ');
const lname = nameParts[nameParts.length-1];
return lastName === lname;
});
console.log(index);
console.log(employees[index]);

mongodb / javascript variable in query

i have:
var optiontable = {1: 'attack', 2: 'defence', 3: 'intelligence'};
var option = 1;
var minion = minions[thisminion]; // get correct, works.
console.log(optiontable[option]); // would output "attack"
var nameoption = optiontable[option];
var increasement = 8;
how would i do to get the minion.attack based on:
thisminion.nameoption // this wont work when it should display the result of thisminion.attack
and get the nameoption to use in:
minions.update({
_id: thisminion._id,
userid: playerid
}, {$inc: {nameoption: increasement}})

Hard to tell without looking at the rest of the code, but looks like you just need to change
thisminion.nameoption
to
thisminion[nameoption]
Since your original line is trying to access thisminion's property called 'nameoption'. Using square brackets would access the property named the same as the value of nameoption.
As for the mongo part: since you can't use a variable as left-hand value, you need to do a little bit of extra work:
var updateObj = {};
updateObj[nameoption] = increasement;
then you can do this:
minions.update({
_id: thisminion._id,
userid: playerid
}, {$inc: updateObj})
Similar questions:
How to set mongo field from variable
Using variables in MongoDB update statement

How to delete a key within an object in local storage with Javascript and/or Jquery?

In local storage I have an object named favourites and it contains this..
"{
"id3333":{
"URL":"somewhere.comm/page1/",
"TITLE":"Page 1 Title",
},
"id4444":{
"URL":"somewhere.comm/page2/",
"TITLE":"Page 2 Title",
}
}"
How can I delete an object based on its ID (id3333 & id4444 for examples)
I have tried the following along with some other voodoo..
localStorage.removeItem('id3333'); // no errors, no removal
localStorage.removeItem('favourites':'id3333'); // SyntaxError: missing ) after argument list
localStorage.removeItem('favourites[id3333]'); // no errors, no removal
localStorage.removeItem('id3333', JSON.stringify('id3333')); // no errors, no removal
Also, I will need to get the key name to delete based on a variable, so like this..
var postID = 'id3333';
localStorage.removeItem(postID);
or
var objectName = 'favourites';
var postID = 'id3333';
localStorage.removeItem(objectName[postID]);
Is it possible to remove a nested item directly or do I need to retrieve the full object and then delete the item and then set the object back to local storage again?
The closest I can get to deleting anything directly so far is..
localStorage.removeItem('favourites');
But that of course removes the entire object.

You have a a single key and you are acting like there are multiple keys
var obj = {
"id3333":{
"URL":"somewhere.comm/page1/",
"TITLE":"Page 1 Title",
},
"id4444":{
"URL":"somewhere.comm/page2/",
"TITLE":"Page 2 Title",
}
};
window.localStorage.favs = JSON.stringify(obj); //store object to local storage
console.log("before : ", window.localStorage.favs); //display it
var favs = JSON.parse(window.localStorage.favs || {}); //read and convert to object
var delKey = "id3333"; //key to remove
if (favs[delKey]) { //check if key exists
delete favs[delKey]; //remove the key from object
}
window.localStorage.favs = JSON.stringify(favs); //save it back
console.log("after : ", window.localStorage.favs); //display object with item removed

With localStorage.removeItem you can only remove top level keys, i.e. keys directly on localStorage.
Because id3333 is on localStorage.favourites you cannot remove it using localStorage.removeItem.
Instead try delete localStorage.favourties['id3333']

Simple, actually: you just delete it. :)
x = {
"id3333":{
"URL":"somewhere.comm/page1/",
"TITLE":"Page 1 Title",
},
"id4444":{
"URL":"somewhere.comm/page2/",
"TITLE":"Page 2 Title",
}
};
console.log(x);
delete x.id3333;
console.log(x);
delete does what you're looking for. You could also do something like delete x.id3333.TITLE if you were so inclined. Note also that delete returns true if successful and false if not.

Suppose you set a nested object in localStorage like that
const dataObj = {
uid: {
name: 'robin',
age: 24,
}
}
window.localStorage.setItem('users', JSON.stringify(dataObj));
Now you want to delete the age property. You can't remove it with removeItem native function since it allows to delete from top level.
So you need to get the data first and delete the property you want and set the data again to localStorage with updated value like that
const existingLocalStorage = JSON.parse(window.localStorage.getItem('users') || {});
if(existingLocalStorage['uid']['age']) { // if throws any error, use lodash get fucntion for getting value
delete existingLocalStorage['uid']['age'];
}
window.localStorage.setItem('users', JSON.stringify(existingLocalStorage));

resolving a javascript and database table logic situation

When I query a database table, I get back values "yes" or "no" for records that represent whether an item is present or not (the item is the column name). I want to create a string that represents the products that are available by name (rather than what I am doing now "kitchen table =" + kitchenTable;
I am thinking this can be solved (poorly) by a series of if statements setting variables to either the product name or to "" and then include all variables in the string
var kt;
if (kitchenTable == yes) kt = "kitchen table";
else kt = "";
if (kitchenCabinet == yes) kc = "kitchen cabinet";
else ka = "";
output = kt + ', ' + kc;
There are about 50 items that can be presented to the user, is there a more efficient way of accomplishing this task?? One option is to change how values are entered into the datbase table such that instead of yes, its the item name but this seems like a poorer way to resolve the issue

Of course you don't give all the details about how do you make query so that is an imaginary mockup of a function simulating query
var available = [];
var result = query("kitchen table");
result === "yes" && ( available.push("kitchen table") );
......
var output = available.join();

What you want is actually built into javascript itself.
I would say using an object literal will really simply your life in this situation by organizing your code and turning it into a more readable format.
I would also recommend turning your server data into true and false as this is a standardized way to communicated a Boolean and allows for the method below to work as it does:
// From server response
var results = {
kitchenCabinet: true,
kitchenTable: true
}
// Use this for your storage of all related items
var kitchenProps = {
kitchenCabinet: 'kitchen cabinet',
kitchenTable: 'kitchen table'
}
// Reuse this function for each time your need a new category (masterBathroomProps...)
function getItemDataIfExists(results, hashTable){
'use strict';
var output = 'Your total is: ';
for (var item in results) {
if (!results.hasOwnProperty(item)) return;
if (results[item]) output += 'A '+hashTable[item]+' ';
}
return output;
}
getItemDataIfExists(results, kitchenProps);
Explanation:
You loop through a result set of an object containing keys names and true false values. In the loop, if the keyname's value is true, then use that keyname to access the properties (in this case a string of your choice. The "key" here is that the key names in each object must line up.
Here is a live demo:
http://codepen.io/nicholasabrams/pen/JXXbYz?editors=0010