Deleting a node simply means taking out the node and rearranging the previous and subsequent node links. If we just remove a node and connect the previous node's next link with the node following the deleted node, we are done with the delete operation. Just have a look at the following example:

When we delete the first node, we just have to make the second node our head or first node. We can achieve that very easily by using the following code:

public function deleteFirst() { 
        if ($this->_firstNode !== NULL) { 
            if ($this->_firstNode->next !== NULL) { 
                $this->_firstNode = $this->_firstNode->next; 
            } else { 
                $this->_firstNode = NULL; 
            } 
            $this->_totalNode--; 
            return TRUE; 
        } 
        return FALSE; 
    } 

Now, we have to consider one special case, namely decreasing the total node count by one.