TypeError: Cannot read properties of undefined (reading 'type')

I need your help with this error I am facing colleagues. I am new to vue so I am finding it quite difficult to solve the error though I what what exactly is causing the error. I am creating a datatable in vue and I am trying to achieve data sorting with this tutorial I am following but end up getting the following error: TypeError: Cannot read properties of undefined (reading 'type')

Kindly refer to this code:

 computed: {
        filteredAccommodations(){
            let accommodations = this.accommodations;
            if (this.search) {
                accommodations = accommodations.filter((row) => {
                    return Object.keys(row).some((key) => {
                        return String(row[key]).toLowerCase().indexOf(this.search.toLowerCase()) > -1;
                    })
                });
            }

            let sortKey = this.sortKey;

            let order = this.sortOrders[sortKey] || 1;
            if(sortKey){
                accommodations = accommodations.slice().sort((a, b) => {
                    let index = this.getIndex(this.columns, 'name', sortKey);
                    a = String(a[sortKey]).toLowerCase();
                    b = String(b[sortKey]).toLowerCase();
                    
                    if (this.columns[index].type && this.columns[index].type === 'date') {
                        return (a === b ? 0 : new Date(a).getTime() > new Date(b).getTime() ? 1 : -1) * order;
                    } else if (this.columns[index].type && this.columns[index].type === 'number') {
                        return (+a === +b ? 0 : +a > +b ? 1 : -1) * order;
                    } else {
                        return (a === b ? 0 : a > b ? 1 : -1) * order;
                    }
                });
            }
            return accommodations;
            
        },

        paginatedAccommodations(){
            return this.paginate(this.filteredAccommodations, this.length, this.pagination.currentPage); 
        }
    },

Counting on your help. Thank you.