A character class matches a single character in the subject; the character must be in the set of characters defined by the class, unless the first character in the class is a cir - cumflex, in which case the subject character must not be inA character class matches a single character in the subject; the character must be in the set of characters defined by the class, unless the first character in the class is a cir - cumflex, in which case the subject character must not be in the set defined by the class.
Une classe de caractères remplace un seul caractère dans la chaîne sujet, à moins que le premier caractère de la classe soit un accent circonflexe ^, qui représente une négation: le caractère ne doit pas se trouver dans la classe.