TypeError: Cannot read properties of undefined (reading 'type') at eval ... at Array.sort (<anonymous>) - vue.js

Question

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')
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);
}
},

Answer 1

The reason for your error is because the value of this.columns[index] is a null value ,Adding a null check in ur if loop might help you solve this but I suggest you to check for the reason of null value.
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] && 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] && 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);
}
},