I do an ajax call in a lightbox script which returns a form.
when the form is loaded I call var initial = $('form').serializeArray();
when the form is submitted I call var final = $('form').serializeArray();
which gives me two arrays of objects,
What I now want to do is compare each object in the arrays and remove those that have not changed.
how would I do this?
I'm assuming that the two arrays will have equal length, and that the elements will be in the same order in both arrays. In this case, what you need to do is look at each element of the first array and compare it to the corresponding element of the second array; if they match, then remove the element in that position from both arrays.
Something like this should work (though I haven't tested it):
var i = 0;
while (i < initial.length) {
if(initial[i] == final[i]) {
initial.splice(i,1);
final.splice(i,1);
}
else {
i++;
}
}
The fastest way to do this I think
var len = initial.length, i=0, changed=[];
/* I hope initial.length==final.length*/
for(i; i<len; i++){
/* 0== '' */
if (initial[i]===final[i])
changed[i] = final[i];
}
//now play with
changed
I've got confused abou the question
does .splice() reorder the indexes?
Related
I have search through quite a lot of questions here, but havent found one that i think fits my bill, so if you know of one please link to it.
I have an array that i want to search through for a specific number and if that number is in the array, i then want to take an action and if not then another action.
I have something like this
var Array = ["1","8","17","14","11","20","2","6"];
for(x=0;x<=Array.length;x++)
{
if(Array[x]==8)
then change picture.src to srcpicture1
else
then change picture.src to srcpicture2
}
but this will run the lenght of the array and end up checking the last element of the array and since the last element is not 8 then it will change the picture to picture2.
Now i can see why this happens, i just dont have any ideas as to how to go about checking if an array contains a specific number.
Thanks in advance.
What you can do is write yourself a function to check if an element belongs to an array:
function inArray(array, value) {
for (var i = 0; i < array.length; i++) {
if (array[i] == value) return true;
}
return false;
}
And the just do:
var arr = ["1","8","17","14","11","20","2","6"];
if (inArray(arr, 8)) {
// change picture.src to srcpicture1
} else {
// change picture.src to srcpicture2
}
It's a lot more readable to me.
For extra points you can add the function to the array prototype like so:
Array.prototype.has = function (value) {
for (var i = 0; i < this.length; i++) {
if (this[i] === value) return true;
}
return false;
};
And then the call would be
if (arr.has(8)) // ...
Pushing this even further, you can check for indexOf() method on array and use it - if not - replace it with the code above.
P.S. Try not to use Array for a variable name, since it's reserved for the actual array type.
use this
http://developer.mozilla.org/En/Core_JavaScript_1.5_Reference/Objects/Array/IndexOf
ie version
https://developer.mozilla.org/En/Core_JavaScript_1.5_Reference/Objects/Array/IndexOf#Compatibility
Why don't just you abort the loop when you find the right number :
for(x=0;x<=Array.length;x++)
{
if(Array[x]==8) {
//change picture.src to srcpicture1
break;
}
}
You could sort the array first then check the array only up to the point at which a number would be in the array, were it to exist.
If you have unique keys and a faster retrieval is what you care about a lot, you can consider using a map instead of an array (if there's a hard-bound case of using an array, then it won't work of course). If using a map, you just check "if( num in arr ) ".
I'm new to javascript so any help would be greatly appreciated.
What I'm trying to do is cycle through every element in the array and count the number of times the value of an element matches a given condition (even if the value is duplicated).
function loaddata(xml) {
var count = 0;
var i;
var xmlDoc = xml.responseXML;
var z = xmlDoc.getElementsByTagName("group");
if (value1 <= value2) {
for (i = 0; i < (0 + z.length); i++) {
if (z[i].getElementsByTagName("name")[0].childNodes[0].nodeValue == "John") {
count++;
}
}
}
$('#count1').html(count);
};
The count value outputted is too small. I believe the reason for this that the for loop isn't iterating through all elements in the array. When I remove the second if loop and output the count for just the for loop this value is also too small. I believe that the for loop isn't searching through the duplicate elements of the array (i.e. it is ignoring them so that they aren't then fed into the second if loop). Is it possible to specify that the for loop include duplicates?
Do a console.log(z[i].getElementsByTagName("name")) and open your browser's console, and see if that array has data in it.
Then console.log(z[i].getElementsByTagName("name")[0].childNodes) and make sure you have nodes in it.
Also, do you have many <group></group> tags? Because that's what you are selecting with var z = xmlDoc.getElementsByTagName("group");
I hope that helps,
I am trying to delete objects from my array via javascript. Im building a simple mobile jquery application and want to delete items from an array. I use the following code. I have a list with checkboxes in it. Every checkbox has a value that belongs to the list item. So when multiple checkboxes are checked.. it should delete all these objects (items) from the array.
function deleteFunction()
{
objects = getObjects();
$("input:checked").each(function()
{
var inputValue = $(this).val();
for(i = getObjects().length; i >=0; i--)
{
if('{"title":"'+ inputValue + '"}' == JSON.stringify(objects[i]))
{
objects.splice(i, 1);
return true;
}
}
});
alert(JSON.stringify(objects));
window.location.reload();
}
The annoying thing is as follows:
When i slice the object from the array, the object is restored on the second iteration. So it always removes only 1 object from the array.
To test my output i used the following code within the if statement:
alert(i);
alert(JSON.stringify(objects[i]));
objects.splice(i, 1);
alert(i);
alert(JSON.stringify(objects));
return true;
The output is as follows
1
{"title":"hi2"}
1
[{"title":"hi1"}, {"title":"hi3"}]
2
{"title":"hi3"}
2
[{"title":"hi1"}, {"title":"hi2"}]
so i slice hi2, but has returned
Thanx for answer and respond
Solution Thanx to depperm + indubitablee:
function deleteFunction()
{
var objects = getObjects();
$("input:checked").each(function()
{
var inputValue = $(this).val();
for(i = objects.length -1; i >=0; i--)
{
if(objects[i].title == inputValue)
{
objects.splice(i, 1);
}
}
});
localStorage.setItem("objects", JSON.stringify(objects));
window.location.reload();
}
There are a few things I would change, first in the for loop no need to call getObjects() each time just use objects. Then in the if simply check if the objects[i].title is the same as the inputValue.
function deleteFunction()
{
objects = getObjects();
$("input:checked").each(function()
{
var inputValue = $(this).val();
for(i = objects .length; i >=0; i--)
{
if(objects[i].title==inputValue)
{
objects.splice(i, 1);
}
}
});
alert(JSON.stringify(objects));
window.location.reload();
}
use .splice() instead of .slice().
slice does NOT alter/manipulate the original array at all, it just creates another array based on your selection.
splice does alter the original array.
reference: http://www.devcurry.com/2010/12/slice-and-splice-in-javascript.html
The array method slice does not remove array elements. Use splice instead.
There are some problems with your code:
You missed the keyword var sometimes.
The variable i is equal to the length of the array in the first iteration. It should be one minus that.
Instead of converting to JSON to compare the objects, you could have just compared the value of the title property.
Im looking for a javascript/jquery (doesn't matter which way) to collect all the files i've uploaded.
I have the following code, where .afbeelding is the class for a couple of file input fields
var geuploadeAfbeeldingen = $('.afbeeldingen').files;
for (var i = 0; i < geuploadeAfbeeldingen.length; i++) {
}
This somehow doesnt seem to work. When i try document.getElementsByClassName it also doesn't work. The funny thing however is, that document.getElementById seem to work on one input field
Any ideas?
This should do what you want
var files = [],
geuploadeAfbeeldingen = $('.afbeeldingen').each(function(){
for (var i = 0; i < this.files.length; i++){
files.push(this.files[i]);
}
});
You end up with an array (files) that holds each file you have selected through the input elements..
Demo at http://jsfiddle.net/gaby/GJW7Y/1/
If you only want the filenames then change
files.push(this.files[i]);
with
files.push(this.files[i].name);
Try this way :
var geuploadeAfbeeldingen = $('.afbeeldingen');
for (var i = 0; i < geuploadeAfbeeldingen.length; i++) {
alert(geuploadeAfbeeldingen[i].files[0].name);
}
This may help you.
Edit :
$('.afbeeldingen').files is not work and document.getElementById().files is worked because first one return JQuery object( array of objects) and second one return DOM object.The jQuery object (created by the $ method) is a wrapper around a DOM element or a set of DOM elements. The normal properties and methods are not available with JQuery object.
You need to loop through each input element and return the files property.
Something like this is probably the shortest way, using map to iterate through an array:
var geuploadeAfbeeldingen = $('.afbeeldingen').map(function(k, v) { return v.files[0]; }).get();
I have an array called "selectMe" formed by a variable wich contains a string such as: 12P, 5B, 10C, etc., this is the "href" value of a hyperlink and I need to find and add the class "selected" to the ones inside this array. To break the array I have:
function selectPrevious(selections){
// split into array
var selectMe = selections.split(", ")
for (var i = 0; i < selectMe.length; i++){
$('#theater a').search(selectMe[i]).addClass('selected');
}
}
I've tried doing find() instead of search() as well as many other iterations but still haven't been able to accomplish what I want, how can I do it?
EDIT
Using one of the answers provided here I have changed it to this:
function selectPrevious(selections){
// split into array
if(typeof selections !== "undefined"){
var selectMe = selections.split(", ");
for (var i = 0; i < selectMe.length; i++){
$('#theater a[href*='+selectMe[i]+']').addClass('selected');
}
}
}
I had to add the "if(typeof selections !== "undefined")" because otherwise it was throwing me errors on IE. Anyway, I still can't add the class "selected" to the values in the array, am I missing something? or did I do something wrong?
Your selector for find() is wrong. And there are no search() in jQuery.
Instead of $('#theater a').search(selectMe[i]) use $('#theater a[href*='+selectMe[i]+']')
try this one:
function selectPrevious(selections) {
// split into array
var selectMe = selections.split(", ")
for (var i = 0; i < selectMe.length; i++){
$('#theater').find('a[href*='+selectMe[i]+']').addClass('selected');
}
}