iOS Objective-C 正则表达式指南

1. 语法

2. 模式

2.1 Search

+ (NSString *)getDomainOfEmailAddress:(NSString *)email
{
    NSString *re = @"(?<=@)((?:[A-Za-z0-9]+(?:[\\-|\\.][A-Za-z0-9]+)*)+\\.[A-Za-z]{2,6})$";
    NSRange range = [email rangeOfString:re options:NSRegularExpressionSearch];
    if (range.location != NSNotFound) {
        return [email substringWithRange:range];
    }
    else {
        return nil;
    }
}

2.2 Match

+ (BOOL)isEmailAddress:(NSString *)email
{
    NSString *re = @"<span style="font-family: Arial, Helvetica, sans-serif;">^([A-Za-z0-9\\.\\-_]{1,})@((?:[A-Za-z0-9]+(?:[\\-|\\.][A-Za-z0-9]+)*)+\\.[A-Za-z]{2,6})$</span><span style="font-family: Arial, Helvetica, sans-serif;">";</span>
    NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", re];

    return [emailTest evaluateWithObject:email];
}