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!
Related
I'm relatively new to customizing Google sheets and only learning javascript.
I'm trying to create a custom function that will search for a value in an array and return a string (something like vlookup).
What I'm trying to achieve is to get the value checked against multiple arrays. I wrote the below but for some reason, it checks only first element of the array (it did work but stopped for some reason and I cannot figure out why as I don't think I changed anything).
The second part will be trickier still, how to make it work against multiple arrays... I was thinking to create an array:
depots = [depot1,depot2...] and then change the code to "depots.length in for loop but even 1 array proves to be problematic.
var depot1 = ["device1", "device2", "device3"];
var depot1 = ["device1", "device2", "device3"];
function _depot(value) {
if (value) {
var depotCheckCase = value.toUpperCase();
for (var i = 0; i < depot1.length; i++) {
if (depotCheckCase == depot1[i]) {
return "Depot 1";
} else {
return false;
}
}
}
}
It only checks the first entry because you have return in both branches of your if/else, so no matter what, the first loop iteration will terminate the function.
Instead, move the return false; to the end, outside of the loop.
A couple of other issues:
You're declaring the same variable twice. Your second var depot1 = ... ends up being just an assignment (but since the array it's assigning has the same entries as the first one, you may not notice).
You're forcing the value to check to upper case, but not doing the same to the entry you're checking against.
Addressing all of those:
var depot1 = ["device1", "device2", "device3"];
function _depot(value) {
if (value) {
var depotCheckCase = value.toUpperCase();
for (var i = 0; i < depot1.length; i++) {
if (depotCheckCase == depot1[i].toUpperCase()) {
return "Depot 1";
}
}
return false;
}
}
console.log(_depot("device2")); // "Depot 1"
console.log(_depot("device8")); // false
Any idea how can I combine it with checking against second/third array?
You have two options:
Additional loops (simplest).
Finding the length of the longest array, using that as the loop max, and checking against undefined before comparing. Since [n] on an array when n is greater than or equal to the length will give you undefined, you can check that before doing the toUpperCase.
Here's that second one:
var depot1 = ["device1", "device2", "device3"];
var depot2 = ["device4", "device5"];
var depot3 = ["device6", "device7", "device8", "device9"];
function _depot(value) {
if (value) {
var depotCheckCase = value.toUpperCase();
var max = Math.max(depot1.length, depot2.length, depot3.length);
var entry;
for (var i = 0; i < max; i++) {
entry = depot1[i];
if (entry !== undefined && depotCheckCase === entry.toUpperCase()) {
return "Depot 1";
}
entry = depot2[i];
if (entry !== undefined && depotCheckCase === entry.toUpperCase()) {
return "Depot 2";
}
entry = depot3[i];
if (entry !== undefined && depotCheckCase === entry.toUpperCase()) {
return "Depot 3";
}
}
return false;
}
}
console.log(_depot("device2")); // "Depot 1"
console.log(_depot("device8")); // "Depot 3"
console.log(_depot("device5")); // "Depot 2"
console.log(_depot("device10")); // false
You could give yourself an array of arrays and do that in a loop rather than repeating the logic. I leave that as an exercise for the reader. :-)
I am trying to using a for loop for trying to validate the input of the user and this is the code i got.
function Valid() {
objfieldid = ["userMail", "userCont"]
objboxid = ["cancelMail", "cancelCont"]
return objfieldid.every(callnonvalid)
}
function callnonvalid(id) {
var valid = false
var objlength = objfieldid.length
objlength--;
for (var i = objlength; i >= 0; i--){
var cobj = document.getElementById(objboxid[i]).checked;
if (document.getElementById(id).value != "" ){
var obj = document.getElementById(id).value;
} else if (cobj == true) {
alert(i); //return 1, 1
return true
} else {
return false
}
}
}
As you can see, in the code, the for loop is running twice. but the i variable is left unchanged. Why would this happen?
btw, I did read different material about closure and i am sure there didnt got a closure problem
EDIT:guys please note that i did noticed the array is zero based, and i did minus the objlength by one.
Mistakes were found after checking the code carefully. The Mistake that I made was that I should not use the return for the out since that would stop the function from working, however that array.every Called the function twice which make the i not decreasing
I'm not sure why you're decrementing in your loop, because the performance gain would be infinitesimally small (it may even be slower, e.g. in Chrome/V8) and working in reverse order can get confusing further down the line, but that's your choice and I don't know enough about what you're doing to judge.
Either way, I don't think you'd want to decrement objlength before the loop begins as you are doing now. The whole point of a loop is to handle the incrementing/decrementing in the condition statement of the loop.
You would only decrement manually like that if you were going to move your if/else if/else statement into a closed over function and execute it recursively, decrementing the objlength from within the closure. Which would work, but it's unnecessarily complicated for what you're doing and you would gain nothing for rewriting the whole thing.
So, sticking with the looping approach, perhaps try either of these:
function Valid() {
objfieldid = ["userMail", "userCont"];
objboxid = ["cancelMail", "cancelCont"];
return objfieldid.every(callnonvalid);
}
function callnonvalid(id) {
var valid = false;
var objlength = objfieldid.length;
for(var i = 0; i < objlength; i++){
var cobj = document.getElementById(objboxid[i]).checked;
if (document.getElementById(id).value != "" ){
var obj = document.getElementById(id).value;
} else if (cobj == true) {
alert(i);
return true;
} else {
return false;
}
}
}
or, if you want to decrement, use while instead of for:
function Valid() {
objfieldid = ["userMail", "userCont"];
objboxid = ["cancelMail", "cancelCont"];
return objfieldid.every(callnonvalid);
}
function callnonvalid(id) {
var valid = false;
var i = objfieldid.length;
while(i--){
var cobj = document.getElementById(objboxid[i]).checked;
if (document.getElementById(id).value != "" ){
var obj = document.getElementById(id).value;
} else if (cobj == true) {
alert(i);
return true;
} else {
return false;
}
}
}
Because the array objboxid[] has only two elements, the first time through your loop objboxid[2] will be attempting to fetch an array index that is out-of-bounds.
You probably meant something like:
for (var i = objlength; i > 0; i--){
var cobj = document.getElementById(objboxid[i-1]).checked;
or perhaps
for (var i = objlength-1; i >= 0; i--){
var cobj = document.getElementById(objboxid[i]).checked;
I have an array of shots. I have been able to take that array and loop through it to get all shots that occurred on hole #1 and then rearrange them in order based on "shot_number". I now need to do this for every hole and to create an array for each hole (ex: holeArray1, holeArray2). I have attempted a number of solutions to increment x but if I do I end up missing some shots that occurred on certain holes.
How can I refactor this function to create this array for every hole without just copying and pasting the code and changing the variable x myself? Thank you for your help. I know I should be able to figure this one out but am struggling.
$scope.createHoleShotsArrays = function () {
var i = 0;
var x = 1;
var holeArray = [];
var len = $scope.shots.length;
for (; i < len; i++) {
if ($scope.shots[i].attributes.hole == x) {
holeArray.push($scope.shots[i]);
holeArray.sort(function (a, b) {
if (a.attributes.shot_number > b.attributes.shot_number) {
return 1;
}
if (a.attributes.shot_number < b.attributes.shot_number) {
return -1;
}
// a must be equal to b
return 0;
});
}
}
console.log(holeArray);
};
Push the items you want into arrays, and sort them once. I don't have cases to test the code. You may modified it a little if something goes wrong.
$scope.createHoleShotsArrays = function() {
var holeArrays = [];
$scope.shots.forEach(function(shot) {
if (holeArrays.length < shot.attributes.hole) {
holeArrays[shot.attributes.hole - 1] = [];
}
holeArrays[shot.attributes.hole - 1].push(shot);
});
holeArrays.forEach(function(arr) {
arr.sort(function(a, b) {
return a.attributes.shot_number - b.attributes.shot_number;
});
});
console.log(holeArrays);
};
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);
}
});
Okay, I am trying to create a sorting application but, its kinda busting my mind. Maybe because of thinking too much.
What I wanted
I want to sort values from an array, maybe using bubble sort
I want to push each iteration to <tr> of a table
and be able to know which values has been replaced
What must happen
Each iteration, I will get a list of values
each list will highlight the values affected
What I currently have
var sort = {
init : function() {
sort.vars.$oldList = [6,4,7,1,8];
sort.play.bubble();
}
}
sort.vars = {
$oldList : new Array(),
$newList : new Array()
}
sort.play = {
bubble : function() {
var list = sort.vars.$oldList;
var n = list.length;
var isSorted = false;
while(!isSorted) {
var tmp, i;
isSorted = true;
for (i = 0; i < n; i++) {
if (list[i] > list[i+1]) {
tmp = list[i];
list[i] = list[i+1];
list[i+1] = tmp;
isSorted = false;
}
sort.ui.pushtToTable(list);
}
}
}
}
sort.ui = {
pushtToTable : function(list) {
$.each(list, function(n, val){
$('tr').append('<td>' + val);
})
}
}
$(document).ready(function(){
sort.init();
})
If possible I wanted to display values one by one, maybe setting a timeout, right?
Yes, setTimeout is a good idea if you want to "see" the algorithm's progress. However, setTimeout only accepts functions as arguments, so each iteration of the sorting algorithm has to be performed in a separate function. See the following code for an example (the code doesn't produce output in each iteration, instead it "animates" the swapping action - but I'm sure you can easily adjust this to fit your needs).
DEMO (JSFiddle)
var SORT = function(type, list, selector){
var container, containerTr, animSteps = [];
// Show all elements in the container
var printArray = function(list){
var str = ["<table>"], i = 0, l = list.length;
for (i; i < l; ++i) {
str.push("<tr><td>", list[i], "</td></tr>");
}
str.push("</table>");
container.html(str.join(""));
};
// This is the interesting part... ;)
var swap = function(list, i1, i2) {
var tmp = list[i1];
list[i1] = list[i2];
list[i2] = tmp;
// Add 3 functions for each swapping action:
// 1. highlight elements, 2. swap, 3. remove highlight
animSteps.push(function(){
containerTr.eq(i1).add(containerTr.eq(i2)).addClass("highlight");
}, function(){
var tmp = containerTr.eq(i1).text();
containerTr.eq(i1).text(containerTr.eq(i2).text());
containerTr.eq(i2).text(tmp);
}, function(){
containerTr.eq(i1).add(containerTr.eq(i2)).removeClass("highlight");
});
};
var animation = function(){
// Execute all iteration functions one after another
if (animSteps.length) {
setTimeout(function(){
animSteps.splice(0,1)[0]();
animation();
}, 250);
}
};
// Collection of sorting algorithms
var algorithms = {
bubblesort: function(list) {
for (var n = list.length; n > 1; --n) {
for (var i = 0; i < n-1; ++i) {
if (list[i] > list[i+1]) {
swap(list, i, i+1);
}
}
}
}
// Add more algorithms using "swap" here...
};
if (algorithms[type] != undefined) {
container = $(selector);
printArray(list);
containerTr = container.find("tr");
algorithms[type](list);
this.sorted = list;
animation();
}
};
// Usage:
var s = new SORT("bubblesort", [5,8,2,4,1,9,7,3,0,6], "#container");
console.log(s.sorted); //the sorted array