Javascript Copy Matrix

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In JavaScript , copying an array is not as easy as using the assignment operator (=) to create a duplicate . If you’ve tried this before, you’ll be surprised to find that it only links to the original list. What is the problem ?

In this guide, we will explain how to copy a JavaScript array. We’ll take a look at the code for three JavaScript array copying strategies so you can get started copying arrays.

The problem with copying JavaScript arrays

At one level, the " = & Rdquo; The operator creates a copy of an array in a new variable . However, this is more of a pointer than a copy. This is because the "=" operator creates a reference to an original array. It does not create a duplicate of the existing table.

Let’s try to create a copy of an array using the assignment operator without any other code:

Our code returns:

It seems that our table has been copied. "Fruit" contains all the values ‚Äã‚Äãfrom our "berries" array .

Now let’s try to add an element to the "fruits" array folder:

We have added "Melon" to the fruit series. Next, we print the values ‚Äã‚Äãfor " fruits " and " berries " to the console:

Both "fruits" and "berries" contain the same values. This is because technically we haven’t cloned our bay. We just created a reference to this one.

Each time we manipulate the "berries" array , the changes will be made in the field of the "fruits" array .

How to copy a JavaScript array

The assignment operator does not copy an array. We have to use another approach. Lucky for us, there are plenty of ways to make a copy of a painting. The three main approaches are:

  • Using the spread operator
  • Using a for loop
  • Using Array.from

Let’s discuss it one by one.

Using the spread operator

The spread operator is a feature introduced in JavaScript ES6. It provides access to content from . an iterable This operator is often used to make a shallow copy of an array

The operator spread has three points as an ellipse (& hellip;).. Let’s create a copy of our "berries" array from before:

We used the spread operator to create a copy of our array. We check the values ‚Äã‚Äãin our arrays to make sure they are correct:

Our code returns:

The value & ldquo; Melon " Has been added only to" fruits " Carrier. In fact, we used the broadcast operator to create a duplicate vector " berries " . Now the table " fruit " is its own table. His values are separated by the tables "berry" .

using a loop

the proven, the use of a for loop is a good way to create a copy of a painting .

This method may not be preferred as a propagation operator because it requires multiple lines of code. However , a for loop does copy an object.

We have declared two lists: berries and fruits. Fruits is initially an empty list. We have so used a for loop to iterate through all the elements of the l iste "berries" . For each item in the list, the value is copied to the "fruit" array folder .

Let’s run our test to see if our arrays are separated:

Our code returns:

Success ! "Berries" and "fruit" are two separate tables.

Using Array.from ()

The method Array.from () turns any iterable object into an array. through each element of an iterable and adds it to a new array. This means it can be used to copy an array.

Let’s create a copy of our "berries" array again:

This solution, like the syntax of the spread operator, requires only two lines of code. It is an efficient and concise way to copy a table. Now let’s go ; s run a test to check our new arrays:

Our code returns:

Our tables have been successfully copied.

Conclusion

Copying an array in JavaScript is easy when you know how to do it.

The assignment operator is not sufficient to copy an array if you want to create a separate version of an array. This is because the assignment operator creates a pointer to an existing array; does not create a new table.

You can create a copy of an array using the spread operator, a for loop, or the Array.from () method. You are now ready to copy tables in JavaScript like an expert.

👻 Read also: what is the best laptop for engineering students?

We hope this article has helped you to resolve the problem. Apart from Javascript Copy Matrix, check other __main__ Python module-related topics.

Want to excel in Python? See our review of the best Python online courses 2023. If you are interested in Data Science, check also how to learn programming in R.

By the way, this material is also available in other languages:



Chen Porretti

Shanghai | 2023-03-29

Thanks for explaining! I was stuck with Javascript Copy Matrix for some hours, finally got it done 🤗. Will get back tomorrow with feedback

Olivia Porretti

Abu Dhabi | 2023-03-29

Thanks for explaining! I was stuck with Javascript Copy Matrix for some hours, finally got it done 🤗. I am just not quite sure it is the best method

Javier OConnell

Berlin | 2023-03-29

Thanks for explaining! I was stuck with Javascript Copy Matrix for some hours, finally got it done 🤗. Will use it in my bachelor thesis

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