ASCII

ASCII (American Standard Code for Information Interchange) is a text coding standard that forms the basis of digital communication. It is used worldwide to encode text data consistently, allowing computers and other devices to exchange information seamlessly. In this blog, we explain what ASCII is, why it's important and how it works, with practical examples and insights for IT professionals, developers, entrepreneurs and tech enthusiasts.

ASCII is a character set that converts each character, number or symbol into a unique binary code. This makes it possible to store and process text information in digital systems. The standard was developed in 1963 by the American National Standards Institute (ANSI) and is still used worldwide.

How does ASCII work?

ASCII uses 7 bits to encode characters, resulting in 128 possible combinations (from 0000000 to 1111111). These combinations include:

Uppercase letters (A-Z)
Lowercase letters (a-z)
Numbers (0-9)
Punctuation marks and special characters (!, @, #, etc.)
Control symbols (such as carriage return or line feed)

Example of ASCII codes

Character	Decimal	Hexadecimal	Binary
A	65	41	01000001
B	66	42	01000010
1	49	31	00110001
!	33	21	00100001

This encoding allows computers to understand and correctly display letters, numbers and symbols.

Why is ASCII important?

ASCII plays a crucial role in digital communication because of the following reasons:

1. Standardization

ASCII provides a universal standard for encoding text, allowing different systems and devices to communicate with each other without problems.

2. Compatibility

Virtually all modern programming languages and operating systems understand ASCII, making it a reliable choice for text processing and communication.

3. Scalability

Although ASCII originally supported only 128 characters, it has become the basis for more comprehensive encodings such as UTF-8. Unicode, including UTF-8, builds on ASCII and supports thousands of additional characters for international communication.

Potential challenges.

ASCII does not support diacritics (such as é, ç or ñ) used in many languages.
Non-Latin scripts, such as Cyrillic, Chinese or Arabic, require Unicode.

ASCII in practice: Applications and examples

ASCII can be found in various industries and applications. Here are some common examples:

Web development
Web developers use ASCII to encode characters in HTML, CSS and JavaScript. Special characters such as spaces or symbols are represented by ASCII codes (e.g.,   for a non-breakable space).
Network communication
Network protocols such as HTTP, FTP and SMTP use ASCII codes to exchange text data. This ensures that e-mails and web pages are formatted and displayed correctly.
Databases and storage.
In databases, text data is often stored and retrieved using ASCII codes, especially when simple text strings without special characters are processed.
Programming languages
Many programming languages, such as Python, C++ and Java, use ASCII for string manipulation and text processing. In Python, you can easily query ASCII codes with the ord() function.

Example in Python:

print(ord('A'))  # Output: 65
print(chr(65)) # Output: 'A'

ASCII versus Unicode: What's the difference?

Although ASCII was long the standard, Unicode is now the norm because of the need for a more comprehensive character set. Here are the key differences:

Feature	ASCII	Unicode (UTF-8)
Number of bits	7 bits	8 to 32 bits
Number of characters	128	More than 143.000
Language support	Latin characters only	Global support
Application	Basic text encoding	Modern software and systems

Unicode is backwards compatible with ASCII, allowing legacy systems to still function within modern applications.

The basis for many years

ASCII has been the basis for digital text communication for decades. Although Unicode is now the standard, ASCII remains relevant in systems where simple, consistent text encoding is needed. Understanding ASCII will help you better understand how digital communication works and the transition to modern character encodings.

Complete ASCII Table

Below is the complete ASCII table, including all control characters, numbers, letters, and special symbols. This table serves as a helpful reference when working with character encoding, data transmission, or programming languages that utilize ASCII. The values are displayed in decimal, hexadecimal, and binary formats, along with their corresponding symbols and descriptions.

Use this table to quickly look up ASCII values or gain a deeper understanding of how characters are encoded at a low level.

Control Characters (0–31 + 127)

Decimal	Hex	Binary	Symbol	Description
0	00	00000000	NUL	Null character
1	01	00000001	SOH	Start of Header
2	02	00000010	STX	Start of Text
3	03	00000011	ETX	End of Text
4	04	00000100	EOT	End of Transmission
5	05	00000101	ENQ	Enquiry
6	06	00000110	ACK	Acknowledge
7	07	00000111	BEL	Bell
8	08	00001000	BS	Backspace
9	09	00001001	TAB	Horizontal Tab
10	0A	00001010	LF	Line Feed
11	0B	00001011	VT	Vertical Tab
12	0C	00001100	FF	Form Feed
13	0D	00001101	CR	Carriage Return
14	0E	00001110	SO	Shift Out
15	0F	00001111	SI	Shift In
16	10	00010000	DLE	Data Link Escape
17	11	00010001	DC1	Device Control 1
18	12	00010010	DC2	Device Control 2
19	13	00010011	DC3	Device Control 3
20	14	00010100	DC4	Device Control 4
21	15	00010101	NAK	Negative Acknowledge
22	16	00010110	SYN	Synchronous Idle
23	17	00010111	ETB	End of Transmission Block
24	18	00011000	CAN	Cancel
25	19	00011001	EM	End of Medium
26	1A	00011010	SUB	Substitute
27	1B	00011011	ESC	Escape
28	1C	00011100	FS	File Separator
29	1D	00011101	GS	Group Separator
30	1E	00011110	RS	Record Separator
31	1F	00011111	US	Unit Separator
127	7F	01111111	DEL	Delete

Numbers (0–9) (48–57)

Decimal	Hex	Binary	Symbol	Description
48	30	00110000	0	Digit 0
49	31	00110001	1	Digit 1
50	32	00110010	2	Digit 2
51	33	00110011	3	Digit 3
52	34	00110100	4	Digit 4
53	35	00110101	5	Digit 5
54	36	00110110	6	Digit 6
55	37	00110111	7	Digit 7
56	38	00111000	8	Digit 8
57	39	00111001	9	Digit 9

Uppercase Letters (A–Z) (65–90)

Decimal	Hex	Binary	Symbol	Description
65	41	01000001	A	Uppercase A
66	42	01000010	B	Uppercase B
67	43	01000011	C	Uppercase C
68	44	01000100	D	Uppercase D
69	45	01000101	E	Uppercase E
70	46	01000110	F	Uppercase F
71	47	01000111	G	Uppercase G
72	48	01001000	H	Uppercase H
73	49	01001001	I	Uppercase I
74	4A	01001010	J	Uppercase J
75	4B	01001011	K	Uppercase K
76	4C	01001100	L	Uppercase L
77	4D	01001101	M	Uppercase M
78	4E	01001110	N	Uppercase N
79	4F	01001111	O	Uppercase O
80	50	01010000	P	Uppercase P
81	51	01010001	Q	Uppercase Q
82	52	01010010	R	Uppercase R
83	53	01010011	S	Uppercase S
84	54	01010100	T	Uppercase T
85	55	01010101	U	Uppercase U
86	56	01010110	V	Uppercase V
87	57	01010111	W	Uppercase W
88	58	01011000	X	Uppercase X
89	59	01011001	Y	Uppercase Y
90	5A	01011010	Z	Uppercase Z

Lowercase Letters (a–z) (97–122)

Decimal	Hex	Binary	Symbol	Description
97	61	01100001	a	Lowercase a
98	62	01100010	b	Lowercase b
99	63	01100011	c	Lowercase c
100	64	01100100	d	Lowercase d
101	65	01100101	e	Lowercase e
102	66	01100110	f	Lowercase f
103	67	01100111	g	Lowercase g
104	68	01101000	h	Lowercase h
105	69	01101001	i	Lowercase i
106	6A	01101010	j	Lowercase j
107	6B	01101011	k	Lowercase k
108	6C	01101100	l	Lowercase l
109	6D	01101101	m	Lowercase m
110	6E	01101110	n	Lowercase n
111	6F	01101111	o	Lowercase o
112	70	01110000	p	Lowercase p
113	71	01110001	q	Lowercase q
114	72	01110010	r	Lowercase r
115	73	01110011	s	Lowercase s
116	74	01110100	t	Lowercase t
117	75	01110101	u	Lowercase u
118	76	01110110	v	Lowercase v
119	77	01110111	w	Lowercase w
120	78	01111000	x	Lowercase x
121	79	01111001	y	Lowercase y
122	7A	01111010	z	Lowercase z

Special Characters and Punctuation (32–47, 58–64, 91–96, 123–126)

Decimal	Hex	Binary	Symbol	Description
32	20	00100000	(space)	Space
33	21	00100001	!	Exclamation mark
34	22	00100010	"	Double quote
35	23	00100011	#	Number sign
36	24	00100100	$	Dollar sign
37	25	00100101	%	Percent sign
38	26	00100110	&	Ampersand
39	27	00100111	'	Apostrophe
40	28	00101000	(	Left parenthesis
41	29	00101001	)	Right parenthesis
42	2A	00101010	*	Asterisk
43	2B	00101011	+	Plus sign
44	2C	00101100	,	Comma
45	2D	00101101	-	Hyphen-minus
46	2E	00101110	.	Period
47	2F	00101111	/	Forward slash
58	3A	00111010	:	Colon
59	3B	00111011	;	Semicolon
60	3C	00111100	<	Less-than sign
61	3D	00111101	=	Equals sign
62	3E	00111110	>	Greater-than sign
63	3F	00111111	?	Question mark
64	40	01000000	@	At symbol
91	5B	01011011	[	Left square bracket
92	5C	01011100	\	Backslash
93	5D	01011101	]	Right square bracket
94	5E	01011110	^	Caret
95	5F	01011111	_	Underscore
96	60	01100000	`	Grave accent
123	7B	01111011	{	Left curly brace
124	7C	01111100	\|	Vertical bar
125	7D	01111101	}	Right curly brace
126	7E	01111110	~	Tilde

Frequently Asked Questions

What is an object in programming?

An object in programming is an instance of a class and contains properties (attributes) and functionalities (methods). Objects are used in object-oriented programming (OOP) to combine data and functionality into a single entity.

What are objects in a computer?

In a computer, objects can refer to software entities within OOP, as well as files, windows or system resources managed by the operating system. An object in OOP is a programming concept, while an object in a computer can be interpreted more broadly.

What is the difference between an object and a class?

A class is a blueprint or template from which objects are created. An object is an instance of a class with specific properties and methods. For example, a class Car can be a blueprint, and an object my_car = Car(“Tesla”, “red”) is a specific car with characteristics.

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