freeCodeCamp/guide/english/csharp/linq/all/index.md

title
All

All

Returns true if all the elements in the collection matches the predicate.

Signature

public static bool All<TSource>(this IEnumerable<TSource> source, Func<TSource, bool> predicate);

Example

var fruits = new List<Fruit>() {
    new Fruit() { Id = 1, Name = "Orange",     Color = "Orange", Quantity: 3   },
    new Fruit() { Id = 2, Name = "Strawberry", Color = "Red",    Quantity: 12  },
    new Fruit() { Id = 3, Name = "Grape",      Color = "Purple", Quantity: 25  },
    new Fruit() { Id = 4, Name = "Pineapple",  Color = "Yellow", Quantity: 1   },
    new Fruit() { Id = 5, Name = "Apple",      Color = "Red",    Quantity: 5   },
    new Fruit() { Id = 6, Name = "Mango",      Color = "Yellow", Quantity: 2   }
};

// All Fruit have a quantity greater than 0.
var allFruitsHaveAQuantity = fruits.All(f => f.Quantity > 0); // true
 // All Fruit have the Color Yellow
var allYellow = fruits.All(f => f.Color == "Yellow"); // false