Queryable.All<'TSource> Method (IQueryable<'TSource>, Expression<Func<'TSource, Boolean>>)


Determines whether all the elements of a sequence satisfy a condition.

Namespace:   System.Linq
Assembly:  System.Core (in System.Core.dll)

static member All<'TSource> : 
        source:IQueryable<'TSource> *
        predicate:Expression<Func<'TSource, bool>> -> bool


Type: System.Linq.IQueryable<'TSource>

A sequence whose elements to test for a condition.

Type: System.Linq.Expressions.Expression<Func<'TSource, Boolean>>

A function to test each element for a condition.

Return Value

Type: System.Boolean

true if every element of the source sequence passes the test in the specified predicate, or if the sequence is empty; otherwise, false.

Type Parameters


The type of the elements of source.

Exception Condition

source or predicate is null.

This method has at least one parameter of type Expression<'TDelegate> whose type argument is one of the Func<'T, 'TResult> types. For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<'TDelegate>.

The All<'TSource>(IQueryable<'TSource>, Expression<Func<'TSource, Boolean>>) method generates a MethodCallExpression that represents calling All<'TSource>(IQueryable<'TSource>, Expression<Func<'TSource, Boolean>>) itself as a constructed generic method. It then passes the MethodCallExpression to the Execute<'TResult>(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

The query behavior that occurs as a result of executing an expression tree that represents calling All<'TSource>(IQueryable<'TSource>, Expression<Func<'TSource, Boolean>>) depends on the implementation of the source parameter's type. The expected behavior is that it determines if all the elements in source satisfy the condition in predicate.

The following code example demonstrates how to use All<'TSource>(IQueryable<'TSource>, Expression<Func<'TSource, Boolean>>) to determine whether all the elements in a sequence satisfy a condition.

No code example is currently available or this language may not be supported.

The Boolean value that the All<'TSource>(IQueryable<'TSource>, Expression<Func<'TSource, Boolean>>) method returns is typically used in the predicate of a where clause (Where clause in Visual Basic) or a direct call to the Where<'TSource> method. The following example demonstrates this use of the All method.

No code example is currently available or this language may not be supported.

Universal Windows Platform
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.1
Windows Phone
Available since 8.1
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