//匹配中级以上强度密码正则表达式，要求数字、字母、特殊字符~@#$^任意两种组合以上     

- (BOOL)passWord:(NSString *)str {   

NSString *passWordRegex = @"^((?![0-9]+$)(?![a-zA-Z]+$)(?![~@#$^]+$))[0-9A-Za-z~@#$^]{8,16}$";    

NSPredicate *regextestmobile =[NSPredicate predicateWithFormat:@"SELF MATCHES %@", passWordRegex];   

if ([regextestmobile evaluateWithObject:str] == YES){       

return YES; 

  }else{ 

  return NO;   

};}