PHP Arrays: Pass by Value or Reference?

Passing and Assigning Arrays in PHP: By Value or Reference

Arrays in PHP can be passed to functions and assigned to variables either by value or by reference. Understanding the difference between the two can be crucial for correctly manipulating arrays.

When Passing Arrays to Functions

When an array is passed to a function as an argument, it is by default passed by value. This means that a copy of the array is created and passed to the function. Any changes made to the array inside the function will not affect the original array outside the function.

However, if you want to pass an array by reference, you need to explicitly use the ampersand (&) operator when passing the argument. This will create a reference to the original array, and any changes made inside the function will be reflected in the original array.

When Assigning Arrays to Variables

When you assign an array to a variable, a copy of the array is created and stored in the new variable. This means that the new variable will not be a reference to the original array, and changes made to one will not affect the other.

However, there is an exception to this rule. If you use the ampersand (&) operator when assigning the array, it will create a reference to the original array. Changes made to either the original array or the new variable will affect both variables.

To summarize:

• Passing arrays to functions: By value (default), By reference (with &)
• Assigning arrays to variables: By value (default), By reference (with &)

Remember that understanding the distinction between passing and assigning arrays by value or reference is essential for efficient and correct manipulation of arrays in PHP.

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