C#如何比较字符串？

Question

There are two log line forms, "Current Employees" and "Projects". They share the same field "Employee ID", which has the same drop down menu with the same values. Drop down values contain IDs of all employees, including former employees. Only those IDs that were used in "Current Employees" log line form belong to current employees. We need to make sure that all projects are assigned to current employees only. How to make this comparison happen? Here is what I have but it doesn't do anything for some reason:

string[] employeeIDs1 =  {"EMP-01", "EMP-02", "EMP-03", "EMP-04", "EMP-05"}; // all employee ID's that exist in the drop down of "Current Employees"
string[] employeeIDs2 =  {"EMP-01", "EMP-02", "EMP-03", "EMP-04", "EMP-05"}; // all employee ID's that exist in the drop down of "Projects"
bool AllFound = true;
int Entries = 0;
bool errorMessage = false;  

for (int i = 0; i < Entries; i++) {
        string[] idEntered1 = new string[Entry.Count];
        string[] idEntered2 = new string[Entry.Count];

        foreach (string s in employeeIDs2) {
            if (String.Equals(s, idEntered1[i], StringComparison.OrdinalIgnoreCase)) {
                AllFound = false;
                break;
            }
        }
}

if (!AllFound) {
    errorMessage = true;
}
else
{
    errorMessage = false;
}

Answer 1

Sorry, I am not sure I understood your problem correctly, You may use LINQ methods to see how many employees are not there in the list as below.

[TestMethod]
public void TestNoOldEmployees_In_List()
{
    string[] employeeIDs1 = { "EMP-01", "EMP-02", "EMP-03", "EMP-04", "EMP-05" };

    string[] employeeIDs2 = { "EMP-01", "EMP-02", "EMP-03", "EMP-04", "EMP-05"};

    var oldEmployeesCount = employeeIDs1.Where(x =>  !employeeIDs2.Contains(x)).Count();

    Assert.AreEqual(0, oldEmployeesCount);
}