c# multiple or statements code example

Example 1: can you have multiple statement in a case c#

switch (value)
{
    case 1: case 2: case 3:          
        // Do Something
        break;
    case 4: case 5: case 6: 
        // Do Something
        break;
    default:
        // Do Something
        break;
}

Example 2: c# if statement with 2 conditions

if (checkbox.checked)
  {
    if (columnname != a && columnname != b && columnname != c)
    {
      "statement 1"
    }
  }
else
  {
    if (columnname != a && columnname != b && columnname != c 
        && columnname != A2)
    {
      "statement 1"
    }
  }