C# Language All


All is used to check, if all elements of a collection match a condition or not.
see also: .Any

1. Empty parameter

All: is not allowed to be used with empty parameter.

2. Lambda expression as parameter

All: Returns true if all elements of collection satisfies the lambda expression and false otherwise:

var numbers = new List<int>(){ 1, 2, 3, 4, 5};
bool result = numbers.All(i => i < 10); // true
bool result = numbers.All(i => i >= 3); // false

3. Empty collection

All: Returns true if the collection is empty and a lambda expression is supplied:

var numbers = new List<int>();
bool result = numbers.All(i => i >= 0); // true

Note: All will stop iteration of the collection as soon as it finds an element not matching the condition. This means that the collection will not necessarily be fully enumerated; it will only be enumerated far enough to find the first item not matching the condition.