0x3D

0x3D is a hexadecimal numeral representing the decimal value 61. The prefix 0x signals base-16 notation in many programming languages and tooling.

In ASCII and Unicode, the code point 0x3D corresponds to the equals sign, '=' (Unicode U+003D). The character is commonly used in text as a symbol for equality in written form, and in source code its meaning as a operator or delimiter depends on the language and context.

In software development, 0x3D is encountered as a numeric literal representing 61 in languages that support hex literals, such as C, C++, Java, JavaScript, Python, and many others. It is also relevant when dealing with byte values and hexadecimal representations in debugging, data parsing, and low-level programming.

In Base64 encoding, the padding character '=' has ASCII decimal value 61, which is 0x3D in hexadecimal. Thus, the hex value 0x3D describes the underlying byte that represents the padding symbol used in Base64-encoded strings.

See also: hexadecimal notation, ASCII, Base64, 0x prefix.