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

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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