Linked Questions
80 questions linked to/from Fastest way to duplicate an array in JavaScript - slice vs. 'for' loop
0
votes
1
answer
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How do I reverse an array in JavaScript while preserving the original value of the original array? [duplicate]
I'm trying to reverse the order of an array using the .reverse() method in JavaScript, but also trying to preserve the original order of elements in the original array. When I save the values into a ...
- 16
0
votes
1
answer
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Copy an array without linking to it [duplicate]
var ProtVar = function(arr){
this.gr1 = [];
this.gr2 = [];
this.arr = arr;
return this;
}
ProtVar.prototype.setArrs = function(){
this.gr1 = this.arr;
this.gr2 = this.arr;
...
- 687
-2
votes
1
answer
1k
views
What is the fastest way to copy an array? [duplicate]
What is the fastest way to copy an array?
I decided to make a game, but I feel that Array.filter is too slow, so I created a method:
Array.prototype.removeIf = function(condition: Function): any[] {
...
- 365
0
votes
1
answer
132
views
How to maintain parent variable value in javascript [duplicate]
I need one clarification java script. I used two variables in my program.
I stored particular array in first variable and again create one variable.
I have stored second variable value in first ...
0
votes
2
answers
94
views
Array value modified even though it was not modified explicitly [duplicate]
I wrote the code below in an attempt to add an element to the beginning of a new array and return that new array. It works fine, but when I return arr instead of newArr, the arr has changed as well.
...
0
votes
0
answers
50
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create for every array in array elemet an extra object strange behavior [duplicate]
Why the first example does not give me the expected result, but the second. They are basically the same. My expected console output of processedData2 should be
[
{
"id": "someid&...
- 93
0
votes
0
answers
43
views
Are these pointers working behind the scene? Javascript [duplicate]
I am trying to find some questions to answer and found myself in a pinch when trying to answer one.
The question is to duplicate a row whenever a certain value in a column is found. And the duplicated ...
- 11.3k
1
vote
0
answers
28
views
Why an array does not reassign in every loop? [duplicate]
Recently I am practicing algorithm questions. There is one that calculates if a string is lexicographically smaller or bigger. I have to find digits, remove them one by one to compare with other ...
- 31
3822
votes
83
answers
2.5m
views
How do I correctly clone a JavaScript object?
I have an object x. I'd like to copy it as object y, such that changes to y do not modify x. I realized that copying objects derived from built-in JavaScript objects will result in extra, unwanted ...
- 40.6k
2165
votes
40
answers
1.3m
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Copy array by value
When copying an array in JavaScript to another array:
var arr1 = ['a','b','c'];
var arr2 = arr1;
arr2.push('d'); // Now, arr1 = ['a','b','c','d']
I realized that arr2 refers to the same array as ...
- 21.9k
394
votes
17
answers
174k
views
Reverse an array in JavaScript without mutating the original array
Array.prototype.reverse reverses the contents of an array in place (with mutation)...
Is there a similarly simple strategy for reversing an array without altering the contents of the original array (...
- 50.1k
126
votes
43
answers
163k
views
Rotate the elements in an array in JavaScript
I was wondering what was the most efficient way to rotate a JavaScript array.
I came up with this solution, where a positive n rotates the array to the right, and a negative n to the left (-length &...
- 12.5k
94
votes
11
answers
158k
views
Deep copy an array in Angular 2 + TypeScript
I have an array of objects that is an input. Lets call it content.
When trying to deep copy it, it still has a reference to the previous array.
I need to duplicate that input array, and change one ...
- 8,067
68
votes
11
answers
114k
views
Splice an array in half, no matter the size?
I have an array I would like to split in half. So I can position the first half on the right side and the second half on the left side.
I have used the splice function before:
var leftSide = ...
- 3,607
82
votes
8
answers
221k
views
How to copy all items from one array into another?
How can I copy every element of an array (where the elements are objects), into another array, so that they are totally independent?
I don't want changing an element in one array to affect the other.
- 1,293