About PHP's debug_zval_dump and xdebug_debug_zval

Dear masters, I would like to ask why the refcount obtained by debug_zval_dump and xdebug_debug_zval are different?
For example:

<code>   $var = "laruence"; 
   $var_1 = &$var;
   $var_2 = &$var;
   
   $var1 = $var;
   $var2 = $var;
   $var3 = $var;
   $var4 = $var;
   
   //debug_zval_dump得到的refcount等于1
   
   //xdebug_debug_zval得到的refcount等于3
</code>

Although I read online that refcount indicates how many variable names point to this zval container, I still don’t know why the results are inconsistent. I haven't found a detailed introduction to this function. . .

But I have summarized the following rules:

---

About xdebug_debug_zval:

• When there is a variable reference, the result obtained by using xdebug_debug_zval is: is_ref=1;refcount=the number of variable references (counting the variable itself)

For example

<code>   $var = "laruence";    //第1次
   $var_1 = &$var;       //第2次

   $var1 = $var;
   $var2 = $var;
   $var3 = $var;
   $var4 = $var;
</code>

So, from xdebug_debug_zval we can get is_red=1;refcount=2;

• When the variable is not referenced, the result obtained by using xdebug_debug_zval is: is_ref=0;refcount=the number of copies of the variable (counting the variable itself)

For example

<code>   $var = "laruence";     //第1次

   $var1 = $var;          //第2次
   $var2 = $var;          //第3次
   $var3 = $var;          //第4次
   $var4 = $var;          //第5次
</code>

So, from xdebug_debug_zval we can get is_red=0;refcount=5;

About debug_zval_dump:

• When there is a variable reference, the result obtained by using debug_zval_dump is: refcount=1 (always=1)

For example

<code>   $var = "laruence";    
   $var_1 = &$var;       

   $var1 = $var;
   $var2 = $var;
   $var3 = $var;
   $var4 = $var;
</code>

So, from debug_zval_dump we can get: refcount=1;

• When the variable is not referenced, the result obtained by using debug_zval_dump is: refcount = the number of copies of the variable (counting the variable itself) + 1

For example

<code>   $var = "laruence";    //第1次

   $var1 = $var;          //第2次
   $var2 = $var;          //第3次
   $var3 = $var;          //第4次
   $var4 = $var;          //第5次
</code>

So, from xdebug_debug_zval we can get is_red=0;refcount=6;

Reply content:

Dear masters, I would like to ask why the refcount obtained by debug_zval_dump and xdebug_debug_zval are different?
For example:

<code>   $var = "laruence"; 
   $var_1 = &$var;
   $var_2 = &$var;
   
   $var1 = $var;
   $var2 = $var;
   $var3 = $var;
   $var4 = $var;
   
   //debug_zval_dump得到的refcount等于1
   
   //xdebug_debug_zval得到的refcount等于3
</code>

Although I read online that refcount indicates how many variable names point to this zval container, I still don’t know why the results are inconsistent. I haven't found a detailed introduction to this function. . .

But I have summarized the following rules:

---

About xdebug_debug_zval:

• When there is a variable reference, the result obtained by using xdebug_debug_zval is: is_ref=1;refcount=the number of variable references (counting the variable itself)

For example

<code>   $var = "laruence";    //第1次
   $var_1 = &$var;       //第2次

   $var1 = $var;
   $var2 = $var;
   $var3 = $var;
   $var4 = $var;
</code>

So, from xdebug_debug_zval we can get is_red=1;refcount=2;

• When the variable is not referenced, the result obtained by using xdebug_debug_zval is: is_ref=0;refcount=the number of copies of the variable (counting the variable itself)

For example

<code>   $var = "laruence";     //第1次

   $var1 = $var;          //第2次
   $var2 = $var;          //第3次
   $var3 = $var;          //第4次
   $var4 = $var;          //第5次
</code>

So, from xdebug_debug_zval we can get is_red=0;refcount=5;

About debug_zval_dump:

• When there is a variable reference, the result obtained by using debug_zval_dump is: refcount=1 (always=1)

For example

<code>   $var = "laruence";    
   $var_1 = &$var;       

   $var1 = $var;
   $var2 = $var;
   $var3 = $var;
   $var4 = $var;
</code>

So, from debug_zval_dump we can get: refcount=1;

• When the variable is not referenced, the result obtained by using debug_zval_dump is: refcount = the number of copies of the variable (counting the variable itself) + 1

For example

<code>   $var = "laruence";    //第1次

   $var1 = $var;          //第2次
   $var2 = $var;          //第3次
   $var3 = $var;          //第4次
   $var4 = $var;          //第5次
</code>

So, from xdebug_debug_zval we can get is_red=0;refcount=6;