What a character map or ASCII codes

An ASCII character map is simply a way of keeping all the printable or screen-displayed characters in one list.

All computers store information as sets of 1’s and 0’s (bits), not as the characters we see. A group of 8 bits makes a byte, 4 bits make a nibble, and two nibbles make a byte. In this way in 8 bits we can represent numbers from 0 to 255, to each value the machine assigns a character. Let’s see some example:

  • the number 32 represents a space
  • from number 48 to 57 are the natural numbers from 0 to 9
  • from 65 to 90 are letters from A to Z in uppercase
  • 97 to 122 are lowercase letters a to z

This ordering method is used as a standard so that somehow all computers work in the same way when it comes to working with characters.

Characters do not appear the same on all computers. In order to control exactly which characters are displayed in each HTML code, it is necessary to specify it in the document header. Since there are different types of ASCII characters depending on the language.

For example, to represent the Chinese language, many more characters will be necessary than to represent English. We see an example (ascii map recommended for Europeans):<META http-equiv=”Content-Type” content=”text/html; charset=iso-8859-1″>

The need for an ASCII character map To display some special characters in HTML we can write, for example:

< & > o©

And in the browser it will appear

< & > or ©

Having a map like this can help us when we need to know which number makes which character.
How to use this mapIf you want to write a character from the ascii table you can press the ALT key + the number in DECIMAL, for example: if you press the key combination ALT+126 the character ~ will be written

ASCII code table

ASCII Hex Symbol
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
NUL
SOH
STX
ETX
EOT
ENQ
ACK
BEL
BS
TAB
LF
VT
FF
CR
SO
SI
ASCII Hex Symbol
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
10
11
12
13
14
15
16
17
18
19
1A
1B
1C
1D
1E
1F
DLE
DC1
DC2
DC3
DC4
NAK
SYN
ETB
CAN
EM
SUB
ESC
FS
GS
RS
US
ASCII Hex Symbol
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
20
21
22
23
24
25
26
27
28
29
2A
2B
2C
2D
2E
2F
(space)
!
»
#
$
%
&

(
)
*
+
,

.
/
ASCII Hex Symbol
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
30
31
32
33
34
35
36
37
38
39
3A
3B
3C
3D
3E
3F
0
1
2
3
4
5
6
7
8
9
:
;
<
=
>
?
ASCII Hex Symbol
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
40
41
42
43
44
45
46
47
48
49
4A
4B
4C
4D
4E
4F
@
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
ASCII Hex Symbol
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
50
51
52
53
54
55
56
57
58
59
5A
5B
5C
5D
5E
5F
P
Q
R
S
T
U
V
W
X
Y
Z
[
\
]
^
_
ASCII Hex Symbol
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
60
61
62
63
64
65
66
67
68
69
6A
6B
6C
6D
6E
6F
`
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
ASCII Hex Symbol
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
70
71
72
73
74
75
76
77
78
79
7A
7B
7C
7D
7E
7F
p
q
r
s
t
u
v
w
x
y
z
{
|
}
~

Leave a Reply

Your email address will not be published.

Back to top button