c# negation operator open parenthesis expected

Question

In C#, I'm writing code for negation operator like this, but it show syntax error, '(' expected

DataTable tmp = new DataTable();
var col = tmp.Columns;
if !(col.Contains("COL1") && col.Contains("COL2") && col.Contains("COL3"))
{
    //DO STH
}

If I change to this code the error disappear:

DataTable tmp = new DataTable();
var col = tmp.Columns;
if (!col.Contains("COL1") || !col.Contains("COL2") || !col.Contains("COL3"))
{
    //DO STH
}

Docs from MS seems too simple and I didn't find how to correct the first code.

So why the first code has syntax error, and how to fix it?

Answer 1

an if always starts with a ( so the code should be

DataTable tmp = new DataTable();
var col = tmp.Columns;
if (!(col.Contains("COL1") && col.Contains("COL2") && col.Contains("COL3")))
{
    //DO STH
}