TypeScript Array methods vs Entity Framework Core (EF Core) LINQ methods
Here’s a comparison of TypeScript Array methods vs Entity Framework Core (EF Core) LINQ methods to help you understand them easily.
| Operation | TypeScript (Array Methods) | EF Core (LINQ Methods) | Explanation |
|---|---|---|---|
| Find (single item) | array.find(x => x.id === 1) |
dbContext.Items.FirstOrDefault(x => x.Id == 1) |
Finds the first matching element. |
| Filter (multiple items) | array.filter(x => x.age > 18) |
dbContext.Items.Where(x => x.Age > 18) |
Filters the items based on a condition. |
| Select (Projection) | array.map(x => x.name) |
dbContext.Items.Select(x => x.Name) |
Projects only specific properties. |
| Sort (Ascending) | array.sort((a, b) => a.age - b.age) |
dbContext.Items.OrderBy(x => x.Age) |
Sorts items in ascending order. |
| Sort (Descending) | array.sort((a, b) => b.age - a.age) |
dbContext.Items.OrderByDescending(x => x.Age) |
Sorts items in descending order. |
| Check if any exist | array.some(x => x.age > 18) |
dbContext.Items.Any(x => x.Age > 18) |
Checks if at least one item matches the condition. |
| Check all match | array.every(x => x.age > 18) |
dbContext.Items.All(x => x.Age > 18) |
Checks if all items match the condition. |
| Count | array.length |
dbContext.Items.Count() |
Counts the total number of items. |
| Sum | array.reduce((sum, x) => sum + x.age, 0) |
dbContext.Items.Sum(x => x.Age) |
Sums a property value. |
| Average | array.reduce((sum, x) => sum + x.age, 0) / array.length |
dbContext.Items.Average(x => x.Age) |
Calculates the average of a property. |
| Take N items | array.slice(0, 5) |
dbContext.Items.Take(5) |
Retrieves the first N items. |
| Skip N items | array.slice(5) |
dbContext.Items.Skip(5) |
Skips the first N items. |
| Remove an item | array = array.filter(x => x.id !== 1) |
dbContext.Items.Remove(entity) |
Removes an item (EF Core requires an entity instance). |
| Add an item | array.push(newItem) |
dbContext.Items.Add(newItem) |
Adds a new item to the list. |
| Find Max | Math.max(...array.map(x => x.age)) |
dbContext.Items.Max(x => x.Age) |
Finds the maximum value of a property. |
| Find Min | Math.min(...array.map(x => x.age)) |
dbContext.Items.Min(x => x.Age) |
Finds the minimum value of a property. |
Key Differences:
- TypeScript methods operate on in-memory arrays, whereas EF Core methods operate on the database via IQueryable.
- EF Core translates LINQ to SQL queries, making it more efficient for database operations.
- TypeScript manipulates data in memory, so operations are performed on already retrieved data.
Memorizing this comparison will help you easily switch between TypeScript and EF Core when working with arrays and database collections.
Happy coding!
