# **📐 Booth: Pascal (1970)** * **Creator:** Niklaus Wirth * **Design Philosophy:** Designed specifically as a pedagogical tool to encourage disciplined, structured programming practices, clear control flow, and data organization. * **Key Innovations:** Explicit user-defined data structures (records, subranges, sets), strict compile-time type-safety, and structured block markers (begin/end, while, repeat). ## **🚀 Hello, World\!** program HelloWorld; begin writeln('Hello, World\!'); end. ## **🎨 Showpiece: Sieve of Eratosthenes** This algorithm finds all prime numbers up to a specified limit ![][image1] using Pascal's native boolean arrays and clean structured loops. The algorithm filters composite numbers to isolate the set of primes: ![][image2]program SieveOfEratosthenes; const LIMIT \= 100; var Primes: array\[2..LIMIT\] of Boolean; I, J: Integer; begin { Initialize all numbers as potentially prime } for I := 2 to LIMIT do Primes\[I\] := True; { Implement the sieve logic } for I := 2 to Trunc(Sqrt(LIMIT)) do begin if Primes\[I\] \= True then begin { Mark all multiples of I starting from I^2 as composite } J := I \* I; while J \<= LIMIT do begin Primes\[J\] := False; J := J \+ I; end; end; end; { Print the results } writeln('Prime numbers up to ', LIMIT, ':'); for I := 2 to LIMIT do begin if Primes\[I\] then write(I, ' '); end; writeln; end. [image1]: [image2]: