Convert a javascript string into a 2-dimensional array - javascript

I have this data coming from a REST method using jquery's getJSON method.
"[Date.UTC(2010,0,0,0,0,0,0), 157],[Date.UTC(2010,0,0,0,0,420,1), 157],[Date.UTC(2010,0,0,0,0,420,2), 282],[Date.UTC(2010,0,0,0,0,600,3), 282],[Date.UTC(2010,0,0,0,0,600,4), 125],[Date.UTC(2010,0,0,0,0,900,5), 125],[Date.UTC(2010,0,0,0,0,900,6), 282],[Date.UTC(2010,0,0,0,0,2100,7), 282],[Date.UTC(2010,0,0,0,0,2100,8), 125],[Date.UTC(2010,0,0,0,0,2400,9), 125],[Date.UTC(2010,0,0,0,0,2400,10), 295],[Date.UTC(2010,0,0,0,0,3600,11), 295],[Date.UTC(2010,0,0,0,0,3600,12), 125],[Date.UTC(2010,0,0,0,0,3900,13), 125],[Date.UTC(2010,0,0,0,0,3900,14), 288],[Date.UTC(2010,0,0,0,0,5100,15), 288],[Date.UTC(2010,0,0,0,0,5100,16), 125],[Date.UTC(2010,0,0,0,0,5400,17), 125]"
It comes back as a string. I need to parse it into a two dimensional array. Each item in the array should have a date and a value.
I also have full control over the REST method, so I could change the way the data returns. I'm interested in making this as fast as possible.
Here's what we are doing now which I think could be improved:
var jqxhr = $.getJSON(getDataURL, function(dataResult) {
var result = dataResult;
result =result.replace(/\]\,\[/g, ']:[');
result = result.replace(/\)\,/g, ');');
var tempArray = result.split(':');
var myarray = new Array();
myarray[0] = new Array(2); // Make the first element an array of two elements
for(i = 0; i < tempArray.length; i ++)
{
myarray[i] = tempArray[i].split(';');
myarray[i][1] = myarray[i][1].replace(/\"/g,'');
myarray[i][1] = myarray[i][1].replace(/\]/g,'');
myarray[i][0] = myarray[i][0].replace(/\[/g,'');
}
})

As much as I'm going to get flack for this (eval tends to be a security risk), I would just do
var myarray = eval("[" + result + "]");

You should use JSON to return data from your server to your JS script. That will be pretty easier to manipulate it as an array.

Related

How to remove all characters before specific character in array data

I have a comma-separated string being pulled into my application from a web service, which lists a user's roles. What I need to do with this string is turn it into an array, so I can then process it for my end result. I've successfully converted the string to an array with jQuery, which is goal #1. Goal #2, which I don't know how to do, is take the newly created array, and remove all characters before any array item that contains '/', including '/'.
I created a simple work-in-progress JSFiddle: https://jsfiddle.net/2Lfo4966/
The string I receive is the following:
ABCD,ABCD/Admin,ABCD/DataManagement,ABCD/XYZTeam,ABCD/DriverUsers,ABCD/RISC
ABCD/ in the string above can change, and may be XYZ, MNO, etc.
To convert to an array, I've done the following:
var importUserRole = 'ABCD,ABCD/Admin,ABCD/DataManagement,ABCD/XYZTeam,ABCD/DriverUsers,ABCD/RISC';
var currentUserRole = importUserRole.split(',');
Using console.log, I get the following result:
["ABCD", "ABCD/Admin", "ABCD/DataManagement", "ABCD/XYZTeam", "ABCD/DriverUsers", "ABCD/RISC"]
I'm now at the point where I need the code to look at each index of array, and if / exists, remove all characters before / including /.
I've searched for a solution, but the JS solutions I've found are for removing characters after a particular character, and are not quite what I need to get this done.
You can use a single for loop to go through the array, then split() the values by / and retrieve the last value of that resulting array using pop(). Try this:
for (var i = 0; i < currentUserRole.length; i++) {
var data = currentUserRole[i].split('/');
currentUserRole[i] = data.pop();
}
Example fiddle
The benefit of using pop() over an explicit index, eg [1], is that this code won't break if there are no or multiple slashes within the string.
You could go one step further and make this more succinct by using map():
var importUserRole = 'ABCD,ABCD/Admin,ABCD/DataManagement,ABCD/XYZTeam,ABCD/DriverUsers,ABCD/RISC';
var currentUserRole = importUserRole.split(',').map(function(user) {
return user.split('/').pop();
});
console.log(currentUserRole);
You can loop through the array and perform this string replace:
currentUserRole.forEach(function (role) {
role = role.replace(/(.*\/)/g, '');
});
$(document).ready(function(){
var A=['ABCD','ABCD/Admin','ABCD/DataManagement','ABCD/XYZTeam','ABCD/DriverUsers','ABCD/RISC'];
$.each(A,function(i,v){
if(v.indexOf('/')){
var e=v.split('/');
A[i]=e[e.length-1];
}
})
console.log(A);
});
You could replace the unwanted parts.
var array = ["ABCD", "ABCD/Admin", "ABCD/DataManagement", "ABCD/XYZTeam", "ABCD/DriverUsers", "ABCD/RISC"];
array = array.map(function (a) {
return a.replace(/^.*\//, '');
});
console.log(array);
var importUserRole = 'ABCD,ABCD/Admin,ABCD/DataManagement,ABCD/XYZTeam,ABCD/DriverUsers,ABCD/RISC';
var currentUserRole = importUserRole.split(',');
for(i=0;i<currentUserRole.length;i++ ){
result = currentUserRole[i].split('/');
if(result[1]){
console.log(result[1]+'-'+i);
}
else{
console.log(result[0]+'-'+i);
}
}
In console, you will get required result and array index
I would do like this;
var iur = 'ABCD,ABCD/Admin,ABCD/DataManagement,ABCD/XYZTeam,ABCD/DriverUsers,ABCD/RISC',
arr = iur.split(",").map(s => s.split("/").pop());
console.log(arr);
You can use the split method as you all ready know string split method and then use the pop method that will remove the last index of the array and return the value remove pop method
var importUserRole = ABCD,ABCD/Admin,ABCD/DataManagement,ABCD/XYZTeam,ABCD/DriverUsers,ABCD/RISC';
var currentUserRole = importUserRole.split(',');
for(var x = 0; x < currentUserRole.length; x++;){
var data = currentUserRole[x].split('/');
currentUserRole[x] = data.pop();
}
Here is a long way
You can iterate the array as you have done then check if includes the caracter '/' you will take the indexOf and substact the string after the '/'
substring method in javaScript
var importUserRole = 'ABCD,ABCD/Admin,ABCD/DataManagement,ABCD/XYZTeam,ABCD/DriverUsers,ABCD/RISC';
var currentUserRole = importUserRole.split(',');
for(var x = 0; x < currentUserRole.length; x++){
if(currentUserRole[x].includes('/')){
var lastIndex = currentUserRole[x].indexOf('/');
currentUserRole[x] = currentUserRole[x].substr(lastIndex+1);
}
}

Is there a way to loop this?

Is there a way to loop a declaration of a variable? just a loop to help me declare the variables so i dont have to do the monotonous work of change the numbers of the variable
var height1 = document.getElementById('height1').value;
var height2 = document.getElementById('height2').value;
var height3 = document.getElementById('height3').value;
var height4 = document.getElementById('height4').value;
var height5 = document.getElementById('height5').value;
var height6 = document.getElementById('height6').value;
var height7 = document.getElementById('height7').value;
var height8 = document.getElementById('height8').value;
var height9 = document.getElementById('height9').value;
var height10 = document.getElementById('height10').value;
var height11 = document.getElementById('height11').value;
var height12 = document.getElementById('height12').value;
var height13 = document.getElementById('height13').value;
var height14 = document.getElementById('height14').value;
var height15 = document.getElementById('height15').value;
var height16 = document.getElementById('height16').value;
This is not a right way of coding that, Just do like,
var heights = [];
Array.from(document.querySelectorAll("input[id^=height]")).forEach(function(itm){
heights.push(itm.value);
});
And now you can iterate the array heights to manipulate the values as per your requirement.
The logic behind the code is, querySelectorAll("input[id^=height]") will select the input elements that has id starts with the text height. Since the return value of querySelectorAll is a nodelist, we have to convert it as an array before using array functions over it. So we are using Array.from(nodelist). That will yield an array for us. After that we are iterating over the returned array by using forEach and pushing all element's value into the array heights.
This is almost always an indication that you want an array. Something like this:
var heights = [];
for (var i = 1; i <= 16; i++) {
heights.push(document.getElementById('height' + i).value);
}
Then you can reference a value from the array with something like:
heights[1]
Though technically since in JavaScript your window-level variables are indexable properties of the window object, you can essentially do the same thing with variable names themselves:
for (var i = 1; i <= 16; i++) {
window['height' + i] = document.getElementById('height' + i).value;
}
Then you can still use your original variables:
height1
Though in the interest of keeping things outside of window/global scope, maintaining the array seems a bit cleaner (and semantically more sensible).
This seems to be a good use case for an object:
var heights = {};
for (var i = 1; i <= 16; i++) {
heights[i] = document.getElementById('height' + i).value;
}
Maybe its time to introduce function:
Generally speaking, a function is a "subprogram" that can be called by code external (or internal in the case of recursion) to the function. Like the program itself, a function is composed of a sequence of statements called the function body. Values can be passed to a function, and the function will return a value.
function getHeight(id) {
return document.getElementById(id).value;
}
Call with the wanted id and use it like a variable.
getHeight('height1')
Normally you would put them in an array.
var heights = []
for (i = 1; i < 17; i++) {
heights[i] = document.getElementById('height' + i).value;;
}
Beware this will give you a hole at the start of the array ie heights[0] has nothing in it. If you use this to iterate it won't matter...
for (var i in heights) {
alert(heights[i]);
}

How to get the 'Value' using 'Key' from json in Javascript/Jquery

I have the following Json string. I want to get the 'Value' using 'Key', something like
giving 'BtchGotAdjust' returns 'Batch Got Adjusted';
var jsonstring=
[{"Key":"BtchGotAdjust","Value":"Batch Got Adjusted"},{"Key":"UnitToUnit","Value":"Unit To Unit"},]
Wow... Looks kind of tough! Seems like you need to manipulate it a bit. Instead of functions, we can create a new object this way:
var jsonstring =
[{"Key":"BtchGotAdjust","Value":"Batch Got Adjusted"},{"Key":"UnitToUnit","Value":"Unit To Unit"},];
var finalJSON = {};
for (var i in jsonstring)
finalJSON[jsonstring[i]["Key"]] = jsonstring[i]["Value"];
You can use it using:
finalJSON["BtchGotAdjust"]; // Batch Got Adjusted
As you have an array in your variable, you have to loop over the array and compare against the Key-Property of each element, something along the lines of this:
for (var i = 0; i < jsonstring.length; i++) {
if (jsonstring[i].Key === 'BtchGotAdjust') {
console.log(jsonstring[i].Value);
}
}
By the way, I think your variable name jsonstring is a little misleading. It does not contain a string. It contains an array. Still, the above code should give you a hint in the right direction.
Personally I would create a map from the array and then it acts like a dictionary giving you instantaneous access. You also only have to iterate through the array once to get all the data you need:
var objectArray = [{"Key":"BtchGotAdjust","Value":"Batch Got Adjusted"},{"Key":"UnitToUnit","Value":"Unit To Unit"}]
var map = {}
for (var i=0; i < objectArray.length; i++){
map[objectArray[i].Key] = objectArray[i]
}
console.log(map);
alert(map["BtchGotAdjust"].Value)
alert(map["UnitToUnit"].Value)
See js fiddle here: http://jsfiddle.net/t2vrn1pq/1/

Arrays and Localstorage

I'm having a little problem here, i have an array like this:
function crearObjetos()
{
var palabraPeso = "peso";
var palabraFecha = "Fecha";
var localStorageKey000 = "objetosPesoFecha";
var contador = 0;
var pesoFecha = new Array(); //THE ARRAY
while(contador < 365)
{
var nuevoObjeto = new Object;
var fechaActual = new Date();
nuevoObjeto.peso = 0;
nuevoObjeto.fecha = fechaActual;
nuevoObjeto.id = contador;
pesoFecha[contador] = nuevoObjeto; //SAVE OBJECTs IN THE ARRAY
contador = contador +1;
}
if (Modernizr.localstorage)
{
localStorage.setItem(localStorageKey000, pesoFecha); //STORAGE THE ARRAY
}
}
The problem is that, when i try to load the array in local storage, i can't acces any data, all are "undefined" and i don't know why... Here is how i load the data from the array (in this case only the first objetc):
function damePrimerObjetoPesoFecha()
{
//LOAD THE ARRAY FROM LOCAL STORAGE
var localStorageKey000 = "objetosPesoFecha";
var arrayDeObjetos = localStorage.getItem(localStorageKey000);
//CHECK IN AN ALERT IF THE DATA IS OK
alert("El primero que devuelve"+arrayDeObjetos[0].id);
//RETURN THE FIRSTONE
return arrayDeObjetos[0];
}
An array can't be pushed into localStorage just like how it is. You have to use JSON.stringify on it. This line :
localStorage.setItem(localStorageKey000, pesoFecha);
must be changed to
localStorage.setItem(localStorageKey000, JSON.stringify(pesoFecha));
Similarly, when you're retrieving it from localStorage, you must use JSON.parse on it to convert it back to JSON. This line :
var arrayDeObjetos = localStorage.getItem(localStorageKey000);
must be :
var arrayDeObjetos = JSON.parse(localStorage.getItem(localStorageKey000));
Now when you access the first data, you wont get undefined.
Another alternative to this would be jStorage plugin which is wrapper around localStorage. It will take all the parsing problems from you and do it by itself if you pass an array or object to it.
Hope this helps!
localStorage only stores data as string.
You can strinify your array into JSON and save that and then parse it back when you load it
localStorage.setItem(localStorageKey000, JSON.stringify(pesoFecha)); //STORAGE THE ARRAY
var arrayDeObjetos = JSON.parse(localStorage.getItem(localStorageKey000));
LocalStorage can store strings only. You also need to remember that JSON.stringify converts date objects to string, so when deserializing via JSON.parse you need to manually create date for each object from array based on that string.
Firstly:
localStorage.setItem(localStorageKey000, JSON.stringify(pesoFecha));
and then
var arrayDeObjetos = JSON.parse(localStorage.getItem(localStorageKey000));
arrayDeObjetos.forEach(function(objecto){
objecto.fecha = new Date(objecto.fecha );
})
localstorage can only store strings.
If you want to store arrays & objects, you should convert them to JSON.
Here's a small helper:
var LS = {
set: function (key, val) {
return localStorage.setItem(key, JSON.stringify(val));
},
get: function (key) {
return JSON.parse( localStorage.getItem(key) );
}
};
Use it as follows:
// Store the array:
LS.set(localStorageKey000, pesoFecha);
// Retrieve the array:
var arrayDeObjetos = LS.get(localStorageKey000);
Here's the fiddle: http://jsfiddle.net/KkgXU/

How do I store JSON objects in indexedDB?

my return json file looks like this:
var data = [{"col1":"value1","col2":"value1","col3":"value1"},{"col1":"value2","col2":"value2","col3":"value2"},{"col1":"value3","col2":"value3","col3":"value3"}];
without JSON.stringify data looks like this:
[object Object],[object Object],[object Object]
but with it the result.length is not 5 but the total number of characters of the string and that way I cant do the loop
var result = JSON.stringify(data);
for(i=0; i<result.length; i++){
var transaction = db.transaction([STORE], IDBTransaction.READ_WRITE);
var put = transaction.objectStore(STORE).put(result);
};
var data = [{"col1":"value1","col2":"value1","col3":"value1"},{"col1":"value2","col2":"value2","col3":"value2"},{"col1":"value3","col2":"value3","col3":"value3"}];
If you are trying to store each OBJECT, then don't stringify it or anything, it is already in perfect form. Change your for() loop to loop through the data objects.
Kristof Degrave had a good point to put these outside of the actual for loop for performance reasons.
var transaction = db.transaction([STORE], IDBTransaction.READ_WRITE);
var objstore = transaction.objectStore(STORE);
for (i = 0; i < data.length; i++) {
objstore.put(data[i]);
}
For new visitors, suggesting a tad of modification:
IDBTransaction.READ_WRITE has been deprecated so use "readwrite" instead.
Resource: https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API/Using_IndexedDB
Reference:
Older experimental implementations use the deprecated constant
IDBTransaction.READ_WRITE instead of "readwrite".
Also, to reduce the loc (which I mostly prefer), use:
var objstore = db.transaction([STORE], "readwrite").objectStore(STORE);
for (i = 0; i < data.length; i++) {
objstore.put(data[i]);
}

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