How to solve the problem of array reference left by PHP after the Foreach Loop

Source: Internet
Author: User
This article mainly describes the PHP after the Foreach loop to leave an array of reference problems, has a certain reference value, now share to everyone, the need for friends can refer to

eg


Result


Explain:

1.foreach is not a block-level domain, the end of an array reference, $K, $a not free memory

2. When the first reference loop ends, the $a points to the last element of the array 4

3. When the second start cycle (where $ A is already pointing to the last element, is a reference)

The change of the loop 4-times array is:

1-> [1, 2,3,4]

2-> [1,2, 3,4]

3-> [3,3] The third value points to the last element 3 but value is a global reference in the last loop that points to the last element so value=3 will change the value of the last element to 3.

4-> [1,2,3,3]

Precautions:

The 1.foreach implementation principle has an internal pointer concept

2.& 's foreach Loop end pointer points to the last element

How to avoid:

unset ($a) after circulating with &foreach

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