Copying arrays/assigning the 'value' of the array to another.

Thread starter Hiche
Start date Nov 22, 2011
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Array Value

In summary, copying an array creates a new array with the same values and a different reference, while assigning the value of an array to another variable simply points the new variable to the same array in memory. There are a few ways to copy an array in JavaScript, such as using the spread operator or the Array.from() method. However, the assignment operator (=) cannot be used to copy an array. There is a difference between a shallow copy and a deep copy of an array, with a shallow copy only copying the references of the elements and a deep copy copying the values of the elements. To make a deep copy of an array in JavaScript, one can use the JSON.parse and JSON.stringify methods or use recursion to iterate through the original array

Nov 22, 2011

Hiche

Code:

int[] aCopy = new int[a.length];
for (int i = 0; i < a.length; i++)
	aCopy[i] = a[i];

Is this the way to 'copy' an array? Basically, I want the elements inside the the array a to be copied or assigned to the array aCopy.

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Nov 22, 2011

Mark44

Mentor

Insights Author

This should work. Try it out and see.

1. What is the difference between copying an array and assigning the value of an array to another variable?

Copying an array creates a new array with the same values and a different reference, while assigning the value of an array to another variable simply points the new variable to the same array in memory.

2. How can I copy an array in JavaScript?

One way to copy an array in JavaScript is to use the spread operator. For example, let newArray = [...oldArray]; This creates a new array with the same values as the original. Another way is to use the Array.from() method.

3. Can I use the assignment operator (=) to copy an array?

No, the assignment operator (=) simply points the new variable to the same array in memory. This means that changes made to one variable will also affect the other.

4. What is the difference between shallow copy and deep copy of an array?

A shallow copy creates a new array and copies the references of the elements from the original array, while a deep copy creates a new array and copies the values of the elements from the original array. This means that changes made to the original array will not affect the shallow copy, but may still affect the deep copy if the values are objects or arrays.

5. How can I make a deep copy of an array in JavaScript?

One way to make a deep copy of an array in JavaScript is to use the JSON.parse and JSON.stringify methods. For example, let newArray = JSON.parse(JSON.stringify(oldArray)); This converts the array into a string and then back into an array, creating a deep copy. Another way is to use recursion to iterate through the original array and create a new array with the same values.