ASCII·J
74
J
0x4A · 1001010

ASCII 74 — the J character

Uppercase

J is 74 in decimal, 4A in hex and 1001010 in binary. It sits 32 away from j.

A starts at 65 and twenty-six letters follow.

Seven bits

ASCII is seven bits wide, which is why there are 128 of them. The eighth bit was long left for parity.

1001010

One bit — the sixth, worth 32 — separates the cases. Off gives a capital, on gives a lowercase letter.

Kind
Uppercase
Decimal
74
Hexadecimal
0x4A
Octal
112
Binary
1001010
HTML entity
J
URL encoding
J
CSS escape
\4A
With Ctrl held
LF (10)
Case pair
j (106)

The chart

Eight columns for the top three bits, sixteen rows for the bottom four. The capitals column sits right beside the lowercase one — that is the shape of the table.

Codes either side

How to read this

  • Add 32 to a capital and you get the lowercase letter — one bit flips.
  • Digits start at 48, so subtracting 48 from the code gives the number.
  • Holding Ctrl clears the top three bits — that is why Ctrl+I is a tab.
  • Everything under 32, plus 127, draws nothing. Those show their abbreviation instead.

Frequently asked questions

Q. What is the ASCII code for J?

Decimal 74, hex 4A, octal 112, binary 1001010.

Q. How do I write J in HTML?

As J.

Q. How does it go in a URL?

It can stay as it is — this character needs no encoding.

Q. Does J have a partner?

j — the codes are 32 apart.