IEnumerable<T>.SingleOrDefault Method

Unit:: Spring.Collections

Package:: Spring.Base

Overloads

SingleOrDefault	Returns the only element of the sequence, or a default value if the sequence is empty; this method raises an exception if there is more than one element in the sequence.
SingleOrDefault(T)	Returns the only element of the sequence, or a specified default value if the sequence is empty; this method raises an exception if there is more than one element in the sequence.
SingleOrDefault(Predicate<T>)	Returns the only element of the sequence that satisfies a specified condition or a default value if no such element exists; this method raises an exception if more than one element satisfies the condition.
SingleOrDefault(Predicate<T>, T)	Returns the only element of the sequence that satisfies a specified condition, or a specified default value if no such element exists; this method raises an exception if more than one element satisfies the condition.

SingleOrDefault

Returns the only element of the sequence, or a default value if the sequence is empty; this method raises an exception if there is more than one element in the sequence.

Delphi

function SingleOrDefault: T

Returns

The single element of the input sequence, or Default(T) if the sequence contains no elements.

Exceptions

The input sequence contains more than one element.

SingleOrDefault(T)

Returns the only element of the sequence, or a specified default value if the sequence is empty; this method raises an exception if there is more than one element in the sequence.

Delphi

function SingleOrDefault(const defaultValue: T): T

Parameters

defaultValue: T

The default value to return if the sequence is empty.

Returns

The single element of the input sequence, or defaultValue if the sequence contains no elements.

Exceptions

The input sequence contains more than one element.

SingleOrDefault(Predicate<T>)

Returns the only element of the sequence that satisfies a specified condition or a default value if no such element exists; this method raises an exception if more than one element satisfies the condition.

Delphi

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

Parameters

predicate: Predicate<T>

A function to test an element for a condition.

Returns

The single element of the input sequence that satisfies the condition, or Default(T) if no such element is found.

Exceptions

predicate is nil .

More than one element satisfies the condition in predicate .

SingleOrDefault(Predicate<T>, T)

Returns the only element of the sequence that satisfies a specified condition, or a specified default value if no such element exists; this method raises an exception if more than one element satisfies the condition.

Delphi

function SingleOrDefault(const predicate: Predicate<T>; const defaultValue: T): T

Parameters

predicate: Predicate<T>

A function to test an element for a condition.

defaultValue: T

The default value to return if the sequence is empty.

Returns

The single element of the input sequence that satisfies the condition, or defaultValue if no such element is found.

Exceptions

predicate is nil .

More than one element satisfies the condition in predicate .