Syntax Error with XOR

Hello, my script is as follows:

public function loadBlog(XML_URL) {
           
            //Execute if either blog[1] or [2] is NULL
            if ((blogs[0] == NULL) XOR (blogs[1] == NULL)) {

                //Instance new Blog inside the actuelEmptyBlog - where array = NULL
                blogs[actualEmptyBlog] = new Blog(XML_URL);
               
                //Swap actualEmpty and actualToDisplay. After Displaying the new Blog, blogs[actualEmptyBlog] = NULL ---> changeBlog();
                this.actualBlogToDisplay = this.actualEmptyBlog;
                if (this.actualBlogToDisplay == 0) { this.actualEmptyBlog = 1; }
           
                if (this.actualBlogToDisplay == 1) { this.actualEmptyBlog = 0; }
           
            }
           
         }

The errors are: (all in line with) xor

rightparen before ANDOR missing

identifier before rightparen missing

illegal attribute