ASCII 63 — ?

The question mark ends interrogative sentences in written English and has versatile roles across computing. In programming, '?' appears in the ternary conditional operator ('condition ? a : b') used across C, JavaScript, Java, and many other languages. In SQL, '?' serves as a parameter placeholder in prepared statements to prevent injection attacks. In URLs, '?' separates the resource path from the query string. In regular expressions, '?' makes the preceding element optional. In TypeScript, '?' marks optional properties and enables safe optional chaining.

Punctuation marks serve as the structural scaffolding of written language, delineating sentences, clauses, and phrases while conveying emphasis and grouping. In programming, these same characters gain powerful additional roles as operators, statement terminators, delimiters, and syntactic markers that compilers and interpreters rely upon. This dual significance in both natural language and code syntax means punctuation characters carry outsized functional importance relative to their small count in the ASCII character set.

In the ASCII encoding table, Question Mark is assigned code point 63 in decimal (0x3F hexadecimal, 077 octal, 00111111 binary). The 7-bit ASCII standard, first published in 1963 by the American Standards Association, defines exactly 128 characters that remain the foundation of text encoding systems worldwide. UTF-8, the dominant encoding on the modern web, is fully backward compatible with ASCII — every ASCII character is encoded as the identical single byte in UTF-8, guaranteeing that Question Mark works reliably across all operating systems, programming languages, and internet protocols.