LINQ - Standard Operators - Filtering Operators

LINQ - Filtering Operators

The two filtering operators in LINQ are the Where and OfType operators. An example follows.

 ArrayList list = new ArrayList { "Sheraz", new object(), "London", new object() };  
             var query = from name in list.OfType<string>()  
                                     where name == "Sheraz"  
                                     select name;  

Above query returns only "Sheraz" and narrows down the search to strings only.

The Where operator generally translates to a WHERE clause when working with a relational database and has an associated keyword in C# as shown in the code above. The OfType operator can be used to coax a non-generic collection (like an ArrayList) into a LINQ query. Since ArrayList  does not implement IEnumerable, the OfType operator is the only LINQ operator we can apply to the list.OfType is also useful if you are working with an inheritance hierarchy and only want to select objects of a specific subtype from a collection. This includes scenarios where LINQ to SQL or the Entity Framework are used to model inheritance in the database. Both operators are deferred.

American Standard Code Information Interchange (ASCII)

ASCII, Hexadecimal, Characters and their Names

ASCII	Hex	Char	Name
0	00	NUL	Null
1	01	STX	Start of Header
2	02	SOT	Start of Text
3	03	ETX	End of Text
4	04	EOT	End of Transmission
5	05	ENQ	Enquiry
6	06	ACK	Acknowledge
7	07	BEL	Bell
8	08	BS	BackSpace
9	09	HT	Horizontal Tabulation
10	0A	LF	Line Feed
11	0B	VT	Vertical Tabulation
12	0C	FF	Form Feed
13	0D	CR	Carriage Return
14	0E	SO	Shift Out
15	0F	SI	Shift In
16	10	DLE	Data Link Escape
17	11	DC1	Device Control 1 (XON)
18	12	DC2	Device Control 2
19	13	DC3	Device Control 3 (XOFF)
20	14	DC4	Device Control 4
21	15	NAK	Negative acknowledge
22	16	SYN	Synchronous Idle
23	17	ETB	End of Transmission Block
24	18	CAN	Cancel
25	19	EM	End of Medium
26	1A	SUB	Substitute
27	1B	ESC	Escape
28	1C	FS	File Separator
29	1D	GS	Group Separator
30	1E	RS	Record Separator
31	1F	US	Unit Separator
32	20	[Space]	Space
33	21	!	Exclamation mark
34	22	"	Quotes
35	23	#	Hash
36	24	$	Dollar
37	25	%	Percent
38	26	&	Ampersand
39	27	'	Apostrophe
40	28	(	Open bracket
41	29	)	Close bracket
42	2A	*	Asterisk
43	2B	+	Plus
44	2C	,	Comma
45	2D	-	Dash
46	2E	.	Full stop
47	2F	/	Slash
48	30	0	Zero
49	31	1	One
50	32	2	Two
51	33	3	Three
52	34	4	Four
53	35	5	Five
54	36	6	Six
55	37	7	Seven
56	38	8	Eight
57	39	9	Nine
58	3A	:	Colon
59	3B	;	Semi-colon
60	3C	<	Less than
61	3D	=	Equals
62	3E	>	Greater than
63	3F	?	Question mark
64	40	@	At
65	41	A	Uppercase A
66	42	B	Uppercase B
67	43	C	Uppercase C
68	44	D	Uppercase D
69	45	E	Uppercase E
70	46	F	Uppercase F
71	47	G	Uppercase G
72	48	H	Uppercase H
73	49	I	Uppercase I
74	4A	J	Uppercase J
75	4B	K	Uppercase K
76	4C	L	Uppercase L
77	4D	M	Uppercase M
78	4E	N	Uppercase N
79	4F	O	Uppercase O
80	50	P	Uppercase P
81	51	Q	Uppercase Q
82	52	R	Uppercase R
83	53	S	Uppercase S
84	54	T	Uppercase T
85	55	U	Uppercase U
86	56	V	Uppercase V
87	57	W	Uppercase W
88	58	X	Uppercase X
89	59	Y	Uppercase Y
90	5A	Z	Uppercase Z
91	5B	[	Open square bracket
92	5C	\	Backslash
93	5D	]	Close square bracket
94	5E	^	Caret / hat
95	5F	_	Underscore
96	60	`	Grave accent
97	61	a	Lowercase a
98	62	b	Lowercase b
99	63	c	Lowercase c
100	64	d	Lowercase d
101	65	e	Lowercase e
102	66	f	Lowercase f
103	67	g	Lowercase g
104	68	h	Lowercase h
105	69	i	Lowercase i
106	6A	j	Lowercase j
107	6B	k	Lowercase k
108	6C	l	Lowercase l
109	6D	m	Lowercase m
110	6E	n	Lowercase n
111	6F	o	Lowercase o
112	70	p	Lowercase p
113	71	q	Lowercase q
114	72	r	Lowercase r
115	73	s	Lowercase s
116	74	t	Lowercase t
117	75	u	Lowercase u
118	76	v	Lowercase v
119	77	w	Lowercase w
120	78	x	Lowercase x
121	79	y	Lowercase y
122	7A	z	Lowercase z
123	7B	{	Open brace
124	7C	|	Pipe
125	7D	}	Close brace
126	7E	~	Tilde
127	7F	DEL	Delete