How to solve php array reference problem left after foreach loop

This article mainly introduces the reference problem of PHP leaving an array after the foreach loop. It has a certain reference value. Now I share it with you. Friends in need can refer to it

eg:

result:

##Explanation:

1.foreach is not block level Domain, array reference ends, $k, $a does not release memory

2. When the first reference cycle ends, $a points to the last element of the array4

3. When the first reference cycle ends Start the loop for the second time (at this time $a already points to the last element and is a reference)

Loop 4 times. The changes in the array are:

1->

[1,2,3,4]

2-> [1,

2,3,4]

3-> [1,2,

3,3] The third time value points to the last element 3, but value is a global reference that pointed to the last element in the last cycle, so when value=3, the last element will also be The value is changed to 3

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

Notes:

1. The implementation principle of foreach has the concept of internal pointers

2. When the foreach loop ends, the pointer will point to the last element

How to avoid:

After using &foreach loop, unset ($a)

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