PHPThe difference between a value transfer and a reference transfer. When is the value passed
(1)Value transfer: any change to the value within the function area will be ignored outside the function.
(2)Passing by reference: any changes to the value in the range of functions can also reflect these modifications outside the function.
(3)Advantages and disadvantages:
A:When the value is passed, the PHP must copy the value. Especially for large strings and objects, this will be a costly operation.
B.Passing by reference does not require duplicate values, which is good for performance improvement.