while 修饰符 while 修饰符 在第二个版本的循环中(sleep while tired ),要执行的循环代码(sleep )优先于测试条件(while tired )。该语法被称为“while 修饰符”(while modifie)。如果你想要使用此语法执行多个表达式,可以将它们放在 begin 和 end 关键字之间: begin ...
5.4 If, Do, and While Statements 5.4 If, Do, and While Statements Expressions controlling ‘if’, ‘do’, and ‘while’ statements can be of any type (and not just type Boolean).