I have some inputs in my app: <_input code/> + <_input code/> = <_input code/>.
Let's imagine first input name is a, appropriately second and third inputs' names are b and c. I filled my inputs:
7 + x = 12
Is there any way to calculate x value?
What do I want from my script:
It finds variable in inputs' values.
It checks all fields of my form filled properly.
It finds variable in inputs' values.
From given information script calculates value of variable.
How many inputs will be doesn't matter. I just want to find value of x. Is there any library to do this?
function calculcateA(b,c){
return c-b;
}
if(inputA === 'x'){
alert(calculateA(inputB,inputC));
}
And so on... there is nothing wrong with this functions, but I want to automate this proccess like WolframAplha.
The best thing for you, I guess would be to find some library for solving equations. If you are in need to solve bigger sets of equations then maybe something related to linear algebra.
Can't really tell you an exact solution so you will have to search for yourself.
Here is some code that should solve the problem.
function calculate() {
var varIndex = -1;
//Ensure that at least two three arguements are passed
if (arguments.length < 3) {
throw "You need at least three parameters to make an equation";
}
//Make sure that there is only one variable
for (var i = 0; i < arguments.length; i++) {
if (isNaN(arguments[i])) {
if (varIndex != -1) {
throw "You can't have two variables";
return;
}
varIndex = i;
}
}
//If variable has been found
if (varIndex != -1) {
var answer = 0;
//If variable is at the last position, add all constants
if (varIndex == types.length - 1) {
for (var j = 0; j < arguments.length - 1; j++) {
answer = answer + j;
}
} else {
//Otherwise Deduct all values from the last
answer = arguments[arguments.length - 1];
for (var k = 0; k < arguments.length - 1; k++) {
if (k == varIndex) { continue; }
answer = answer - j;
}
}
//Return Result
return { variable: arguments[varIndex], answer: answer };
}
else {
throw "You need at least one variable";
return;
}
}
You would use the above as follows:
var a = document.querySelector("input[name=a]");
var b = document.querySelector("input[name=b]");
var c = document.querySelector("input[name=c]");
var calcBtn = document.getElementById("calculate");
calcBtn.addEventListener("click", function () {
try {
var result = calculate(a.value, b.value, c.value);
console.log("The value of " + result.variable + " is " + result.answer);
} catch (e) {
console.log(e);
}
});
Related
This code takes an integer and returns the amount of 1s that are present.
function countOnes(i) {
let str = i.toString();
let ones = 0;
for(let x = 0; x < i.length; x++) {
if(str.charAt(x) === '1') ones++;
}
return ones;
}
console.log(countOnes(111000));
But it only appears to work in certain executors of JavaScript. If I enter this code into p5.js or Mozilla MDN, I will receive the desired output of 3.
But if I use the console in my browser and some other websites emulating that, 0 will be returned with every given value.
Why is this the case?
you cant loop on i.length, i its still a 'Number' type,
you should loop on "str.length" instead.
you better give more meaningful names... i should be num,
str should be numStr, ones should be counter.
try this:
function countOnes(num) {
var counter = 0;
var numsArray = Array.from((num + ''))
numsArray.forEach(num => {
return (num == 1)? counter++ : ''
})
return counter
}
console.log(countOnes(1110010)); // 4
I have the following code
var utils = require(`${__dirname}/../../utils/utils.js`);
...
let object = utils.parse(input);
if (object === undefined){
let helper = utils.recognize(input);
msg.channel.sendMessage("\"" + input + "\" not recognized. Did you mean \"" + helper[0] + "\"?");
object = utils.parse(helper[0]);
}
//code related to object
console.log(object.strLength);
where "parse" tries to match the input to an object in a database, and "recognize" tries to find the best match if the input is spelled incorrectly (Levenshtein) (along with additional info such as how close the match was).
Currently the issue is that the code is ran asynchronously; "object.strLength" returns an undefined before utils.recognize() returns a value. If I copy/paste the recognize() and parse() functions into the file, then the code is run synchronously and I do not run into any issues. However I would rather keep those functions in a separate file as I reuse them in other files.
Is there a way to specify that the functions in utils must be synch? I know that there are libraries that convert asynch into synch but I prefer to use as few libraries as I can help it. I tried to have the recognize functions return a Promise but it ended up as a jumbled mess
edit: here's parse. I did not think it was necessary to answer this question so I did not include it initially:
var db = require(`${__dirname}/../data/database.js`);
...
var parse = (input) => {
let output = db[output];
if (output === null) {
Object.keys(db).forEach((item) => {
if (db[item].num === parseInt(input) || (db[item].color + db[item].type === input)){
output = db[item];
return false;
}
});
}
return output;
}
I solved the issue, thanks everyone. Here's what was wrong, it was with recognize(). It was my mistake to not show the code for it initially.
Original recognize:
var recognize = (item) => {
//iterate through our databases and get a best fit
let bestItem = null;
let bestScore = 99999; //arbitrary large number
//let bestType = null;
//found algorithm online by milot-mirdita
var levenshtein = function(a, b) {
if (a.length == 0) { return b.length; }
if (b.length == 0) { return a.length; }
// swap to save some memory O(min(a,b)) instead of O(a)
if(a.length > b.length) {
let tmp = a;
a = b;
b = tmp;
}
let row = [];
for(let i = 0; i <= a.length; i++) {
row[i] = i;
}
for (let i = 1; i <= b.length; i++) {
let prev = i;
for (let j = 1; j <= a.length; j++) {
let val;
if (b.charAt(i-1) == a.charAt(j-1)) {
val = row[j-1]; // match
} else {
val = Math.min(row[j-1] + 1, // substitution
prev + 1, // insertion
row[j] + 1); // deletion
}
row[j - 1] = prev;
prev = val;
}
row[a.length] = prev;
}
return row[a.length];
}
//putting this here would make the code work
//console.log("hi");
Object.keys(db).forEach((key) => {
if (levenshtein(item, key) < bestScore) {
bestItem = key;
bestScore = levenshtein(item, key);
}
});
return [bestItem, bestScore];
}
My solution was to move the levenshtein function outside of the recognize function, so if I wanted to I can call levenshtein from another function
#user949300 and #Robert Moskal, I changed the forEach loop into a let...in loop. There is no functional difference (as far as I can tell) but the code does look cleaner.
#Thomas, I fixed the let output = db[output]; issue, oops.
Again, thanks for all of your help, I appreciate it. And happy New Year too
I'm fairly new to JS and am still slightly confused, by the ordering and nesting of JS functions. I have a script that I want to occur in a specific way. The problem a criteria can be left blank by a user. Im trying to say if the variable length is greater than zero run the callback, but then move into the code that occurs under the next two if statements. I know there must be a more efficient method for this, but for the life of me I can't think of one besides placing all the other code under each different if/else statement.
var lst = []
var lst2 = []
var lst3 = []
alert(cityu);
alert(dateu);
alert(numberu);
d3.csv("kyle.csv", function (d) {
return {
city: d.from,
number: d.phone_number,
date: d.from_date
};
}, function (error, rows) {
if (dateu.length > 0) {
for (var i = 0; i < rows.length; i++) {
if (rows[i].date === dateu) {
lst.push(rows[i]);
console.log(rows[i]);
}
}
} else {
if (cityu.length > 0) {
for (var i = 0; i < lst.city.length; i++) {
if (lst.city[i] === cityu) {
lst2.push(lst[i]);
console.log(lst2);
}
}
} else {
if (numberu.length > 0) {
for (var i = 0; i < rows.length; i++) {
if (lst.number[i] === numberu) {
lst3.push(lst2[i]);
console.log(lst3);
}
}
}
}
}
})
};
Here you can see that if the dateu variable has length greater than zero the rows in a csv matching that user entered criteria will be pushed to the array "lst". Obviously it currently doesn't move into the next callback under, it will only do this if "dateu" equalled zero.
One other issue with my script is that at each if statement I hope to reduce my original input based on the user entered parameters. For example a user might enter "seattle" the variable "city" will now equal seattle and only rows containing Seattle as their city will be kept in the array that rows[i] is pushed to.
Every piece of user input shown here:
alert(cityu);
alert(dateu);
alert(numberu);
will have the same affect on the dataset, each time reducing the number of rows included.
The problem specifically is that each if statement relies on the array from the previous callback.
Your code redone a little - I've removed the else blocks, because you want to do each loop regardless of the previous loop
if(condition1) {
do something
}
else {
do something else
}
from that, if the first condition is met, the else block wont get executed
if(condition1) {
do something
}
if(condition2) {
do something else
}
In this case, do something else only relies on condition2 being true, consition1 is irrelevant
var lst = []
var lst2 = []
var lst3 = []
alert(cityu);
alert(dateu);
alert(numberu);
d3.csv("kyle.csv", function(d) {
return {
city: d.from,
number: d.phone_number,
date: d.from_date
};
}, function(error, rows) {
var i;
if (dateu.length > 0) {
for (i = 0; i < rows.length; i++) {
if (rows[i].date === dateu) {
lst.push(rows[i]);
console.log(rows[i]);
}
}
}
if (cityu.length > 0) {
for (i = 0; i < lst.city.length; i++) {
if (lst.city[i] === cityu) {
lst2.push(lst[i]);
console.log(lst2);
}
}
}
if (numberu.length > 0) {
for (i = 0; i < rows.length; i++) {
if (lst.number[i] === numberu) {
lst3.push(lst2[i]);
console.log(lst3);
}
}
}
});
};
One minor inconsequential change, moved the declaration of var i to the top of the function block, because technically you were declaring it three times, and jslint/jshint would complain - though nothing would break (yet)
I'm still not completely sure on your logic, but looking at Tiny Giant's gist, it seems like there are only three combinations:
1) Only dateu exists.
2) dateu and cityu exist.
3) dateu, cityu, and numberu exist.
So you don't care about the condition where dateu and numberu exist, but cityu is empty, right?
Okay, I reread your code. It seems like you have rows, and you have three possible filters. Filter rows based on AND, for example cityu AND dateu.
If so, here's a giant refactor. Just as a note, there may be some JavaScript errors because I had no way of testing this. But the code is fairly simple and straightforward:
var lst = [] // I'm not using these.
var lst2 = []
var lst3 = []
alert(cityu);
alert(dateu);
alert(numberu);
var getActiveFilters = function() {
// Edit possibleFilters as necessary.
// the key should reflect the header of the column
// and the value is a variable referring to the user-inputted string
var possibleFilters = {
'date': dateu,
'city': cityu,
'number': numberu
};
var activeFilters = {};
for (key in possibleFilters) {
if (possibleFilters[key].length > 0) {
activeFilters[key] = possibleFilters[key];
}
}
return activeFilters;
}
// just made this into a function to get it out of the callback
var functionAfterCsv = function(rows) {
var activeFilters = getActiveFilters();
var filteredList = [];
var addRow = false;
for(i = 0; i < rows.length; i++) {
// see if the current row matches all the filters present
for (key in activeFilters) {
if (rows[i][key] === activeFilters[key]) {
addRow = true;
} else {
addRow = false;
// if the row doesn't meet one of the conditions,
// there's no need to check the rest
break;
}
}
if (addRow) {
filteredList.push(row[i]);
}
}
return filteredList;
};
d3.csv("kyle.csv", function (d) {
return {
city: d.from,
number: d.phone_number,
date: d.from_date
};
}, function (error, rows) {
functionAfterCsv(rows);
})
});
If you're filtering using OR, then you'll need to change your comparison to something like this:
for (key in activeFilters) {
if (rows[i][key] === activeFilters[key]) {
addRow = true;
break; // if one is true, that's good enough for an OR
} else {
addRow = addRow || false;
}
}
if (addRow) {
filteredList.push(row[i]);
// reset addRow for the next row
addRow = false;
}
Hope this was closer to your intended logic!
The user's input must look like "value1,value2,value3,valu4..." and value[i]-value[i-1] must be greater than, say, 0.5. Minimum value is 0, maximum is 100. For example, "0,5,10.5,20" is OK. My basic code is
$('.click').click(function () {
var flag = true;
var str = $('input').val();
var arr = str.split(',');
if (arr.length > 1) {
jQuery.each(arr, function (i) {
if (arr[i] < 0 || arr[i] > 100 || arr[i + 1] - arr[i] < 0.5) {
flag = false
}
});
if (flag) {
//main function must never start before we complete that check on all the values
alert("OK, our function starts now. Your input is " + str)
} else {
alert("Please, check your input: " + str)
}
}
});
and this seems to work, but I'm not sure: maybe I'm missing something.
My question is how to force my main function not to start before the array check is finished. Is there a chance for it to start before all numbers in that arr are checked? And maybe there's no need to create that flag, then what would you do to perform this kind of validation?
here is a re-write of what you have, splitting the main algorithm into its own function, and using its return value to display your alerts. Obviously I havent been able to test it as I dont have your web page, but with a bit of luck it should work...
$(document).ready(function() {
$('.click').click(function() {
var str = $('input').val();
if (inputCheck(str)) {
//if true
alert("OK, our function starts now. Your input is " + str);
} else {
alert("Please, check your input: " + str);
}
});
});
function inputCheck(str) {
var arr = str.split(','),
flag = false;
if (arr.length > 1) {
jQuery.each(arr, function(i) {
if (arr[i] < 0 || arr[i] > 100 || arr[i + 1] - arr[i] < 0.5) {
flag = false;
return false;
//exit loops
} else
flag = true;
});
//end each
}//end if
return flag;
}
I can't see any way the execution path could pass the check. However you probably want to check against non-numerical values too and you can get rid of that nested function
$('.click').click(function () {
var str = $('input').val();
var arr = str.split(',');
if (arr.length > 1) {
for(var i=0; i<arr.length; i++) {
if (arr[i]<0 || arr[i]>100 || arr[i+1]-arr[i]<0.5 || !jQuery.isNumeric(arr[i])) {
return alert("Please, check your input: " + str);
}
}
main(str);
}
});
function main(str) { // Just so that this *main function* exists ;)
alert("OK, our function starts now. Your input is " + str);
}
EDIT**
In a game I am creating I use the next question button to move onto other questions in the grid if the user is having trouble with the current one. At the moment I have had real problems with it as it keeps on crashing my program, and not giving any console errors. The last problem I had with it was that it said "too much recursion". Since then I thought I had sorted the problem, but I have just done a few tests and it crashes every time.
This is the click event for the button...
//Next question click event
$('.next-question').bind("click", function() {
$('td').removeClass('highlight-problem');
shuffleEqually(listOfWords);
shuffleEqually(nextWordIndexes);
var rndWord = nextWordIndexes[Math.floor(Math.random())];
var rndWord = nextWordIndexes[2];
//Adds and removes nesesary classes
$('td[data-word="' + listOfWords[rndWord].name + '"]').addClass('highlight-problem');
$('td[data-word=' + word + ']').removeClass('wrong-letter').removeClass('wrong-word').removeClass('right-letter');
var spellSpace = $('td[data-word="' + listOfWords[rndWord].name + '"]').hasClass('right-word');
if (spellSpace) {
$('.next-question').trigger('click');
} else {
$("#hintSound").attr('src', listOfWords[rndWord].audio);
hintSound.play();
$("#hintPic").attr('src', listOfWords[rndWord].pic);
$('#hintPicTitle').attr('title', listOfWords[rndWord].hint);
}
});
I think it may have something to do with the if statement, but have tried changing it to this..
if (spellSpace == false) {
$("#hintSound").attr('src', listOfWords[rndWord].audio);
hintSound.play();
$("#hintPic").attr('src', listOfWords[rndWord].pic);
$('#hintPicTitle').attr('title', listOfWords[rndWord].hint);
}
and it makes it even worse
ShuffleEqually:
//Shuffles words to randomize
shuffleEqually(nextWordIndexes);
var shuffledWords = [];
shuffledWords = chosenWords.sort(function () {
return 0.5 - Math.random();
});
function shuffleEqually(a1, a2) {
var arrays = [];
if (typeof a1 === 'object' && a1.length > 0) {
arrays.push(a1);
}
if (typeof a2 === 'object' && a2.length > 0) {
arrays.push(a2);
}
var minLength = arrays[0].length;
jQuery.each(arrays, function (i, a) {
minLength = a.length < minLength ? a.length : minLength;
});
var randoms = [];
for (i = 0; i < minLength; i++) {
randoms.push(Math.random());
}
jQuery.each(arrays, function (i, a) {
var i = minLength;
while (i--) {
var p = parseInt(randoms[i] * minLength);
var t = a[i];
a[i] = a[p];
a[p] = t;
}
});
};
Hint sound:
var hintSound = $("#hintSound")[0];
Your issue is an infinite loop, plain and simple.
$('.next-question').bind("click", function() {
// binds click...
...
if (spellSpace) {
$('.next-question').trigger('click');
// triggers click ON THE SAME ELEMENT COLLECTION (same selector)
You want to refine this. I assume you want the trigger to work on the next question, so I suggest changing the second statement to:
$(".next-question").eq(($(".next-question").index($(this)) + 1) % $(".next-question").length).trigger("click");
You have a second infinite loop in shuffleEqually:
jQuery.each(arrays, function (i, a) {
var i = minLength;
while (i--) {
var p = parseInt(randoms[i] * minLength);
var t = a[i];
a[i] = a[p];
a[p] = t;
}
Change the while condition to have a limiting value, or it will loop endlessly (as a decrement operation always succeeds).