if else if else condition stop if first if is true

In C#, if ? else if ? else is exclusive.
That means:

• If the first if is true ? all other conditions are skipped.

• else if runs only when previous conditions are false.

If you want to check all conditions, do NOT use else if

Use multiple independent if statements:

if (condition1)
{
    // do something
}

if (condition2)
{
    // do something
}

if (condition3)
{
    // do something
}

Now all conditions will be evaluated, even if the first one is true.

Wrong (skips remaining conditions)

if (condition1)
{
    ...
}
else if (condition2)
{
    ...
}
else if (condition3)
{
    ...
}

Correct (checks all conditions)

if (condition1)
{
    Console.WriteLine("C1 true");
}
if (condition2)
{
    Console.WriteLine("C2 true");
}
if (condition3)
{
    Console.WriteLine("C3 true");
}
else
{
    Console.WriteLine("C3 false");
}

When to keep else if

Use else if only when conditions are mutually exclusive
(only ONE should run).

If you want to check all conditions but run different logic:

Example — checking multiple validation errors:

List errors = new();

if (age < 18)
    errors.Add("Age must be 18+");

if (email == null)
    errors.Add("Email required");

if (!isValidMobile)
    errors.Add("Invalid mobile number");

if (errors.Any())
{
    Console.WriteLine("Validation failed:");
    errors.ForEach(e => Console.WriteLine(e));
}

1. if (UserData.RoleName == aaaaaa)  
2. {  
3.    U1 = true;  
4. }  
5.  
6. else if (UserData.RoleName == bbbbbbbb)  
7. {  
8.    U2 = true;  
9. }  
10. else if (UserData.RoleName == cccccccc)  
11. {  
12.    U3 = true;  
13. }  
14. else if (UserData.RoleName == dddddddd)  
15. {  
16.    U4 = true;  
17. }  
18. else  
19. {  
20.    U5 = true  
21. }