How to useType Assertions in Typescript

Using type assertions to sort an array with null properties involves asserting the property as a defined type and providing a default value if it is null. This ensures TypeScript treats the property as defined for comparison.

Example

JavaScript
interface Item {
    name?: string | null;
    value?: number | null;
}

const items: Item[] = [
    { name: 'item1', value: 10 },
    { name: 'item2', value: null },
    { name: null, value: 5 },
    { name: 'item3', value: 15 },
];

items.sort((a, b) => {
    return (a.value ?? 0) - (b.value ?? 0);
});

console.log(items);

Output:

[
{ name: 'item2', value: null },
{ name: null, value: 5 },
{ name: 'item1', value: 10 },
{ name: 'item3', value: 15 }
]


How to Sort an Array of Objects with Null Properties in TypeScript ?

Sorting an array of objects in TypeScript involves arranging objects based on specified properties. When dealing with null properties, ensure consistency by placing them either at the start or end of the sorted array to maintain predictability in sorting outcomes.

Below are the approaches used to sort an array of objects with null properties in TypeScript:

Table of Content

  • Using Array.prototype.sort with a ternary operator
  • Using Array.prototype.reduce
  • Using Array.prototype.filter() and concat()
  • Using Array.prototype.sort with a custom comparison function
  • Using Type Assertions

Similar Reads

Approach 1: Using Array.prototype.sort with a ternary operator

In this approach, we Sort an array of objects with null properties using Array.prototype.sort and a ternary operator for comparison. Prioritizes sorting based on existing properties or default sorting criteria if properties are null....

Approach 2: Using Array.prototype.reduce

In this approach we uses Array.prototype.reduce with a custom sorting function. It iterates over elements, inserting them into a sorted array based on their properties. Handles cases where properties are null....

Approach 3: Using Array.prototype.filter() and concat()

Filter out objects with null properties, sort the remaining objects based on their non-null property, then concatenate them with objects having null properties to maintain original order....

Approach 4: Using Array.prototype.sort with a custom comparison function

In this approach, we’ll use Array.prototype.sort with a custom comparison function that handles cases where properties are null or undefined. This approach provides flexibility in defining sorting criteria and can handle various scenarios efficiently....

Approach 5: Using Type Assertions

Using type assertions to sort an array with null properties involves asserting the property as a defined type and providing a default value if it is null. This ensures TypeScript treats the property as defined for comparison....

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