/**
* 檢測用戶輸入密碼是否以字母開頭,6-18位數字和字母組合
*正則匹配用戶密碼6-18位數字和字母組合
* @param pattern 傳入需要檢測的字符串
*
* @return 返回檢測結果 是或者不是
*/
+(BOOL)detectionIsPasswordQualified:(NSString *)patternStr{
NSString *pattern = @"^(?![0-9]+$)(?![a-zA-Z]+$)[a-zA-Z0-9]{6,18}";
NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", pattern];
BOOL isMatch = [pred evaluateWithObject:patternStr];
return isMatch;
}