(PHP 5 >= 5.3.0, PHP 7, PHP 8)
shm_has_var — Check whether a specific entry exists
Checks whether a specific key exists inside a shared memory segment.
   Returns true if the entry exists, otherwise false
  
| Version | Description | 
|---|---|
| 8.0.0 | shmexpects a SysvSharedMemory
        instance now; previously, a resource was expected. |