IEnumerable<T>.Single Method

Unit:: Spring.Collections

Package:: Spring.Base

Overloads

Single	Returns the only element of the sequence, and raises an exception if there is not exactly one element in the sequence.
Single(Predicate<T>)	Returns the only element of the sequence that satisfies a specified condition, and raises an exception if more than one such element exists.

Single

Returns the only element of the sequence, and raises an exception if there is not exactly one element in the sequence.

Delphi

function Single: T

Returns

The single element of the sequence.

Exceptions

The input sequence contains more than one element.

-or-

The input sequence is empty.

Single(Predicate<T>)

Returns the only element of the sequence that satisfies a specified condition, and raises an exception if more than one such element exists.

Delphi

function Single(const predicate: Predicate<T>): T

Parameters

predicate: Predicate<T>

A function to test an element for a condition.

Returns

The single element of the sequence that satisfies a condition.

Exceptions

predicate is nil .

No element satisfies the condition in predicate .

-or-

More than one element satisfies the condition in predicate .

-or-

The sequence is empty.