how to remove from a list from a combo box

When trying to write the following code, it comes up with 3 errors. Syntax error on token 'else', insert 'assignmentoperator expression' to complete assignment and that cannot convert from string to boolean. This is for a combo box and when I choose from the combo box, I want to remove the other sites from a list. 'site' is a variable in main and c.site is a parameter in another agent. Can someone explain what to do.

if ( site ) {
	if ( c.site.equals( "x" ) ) {
		cavernIterator.remove();
		continue;
	}
}
else {
	if ( c.site.equals( "y" ) ) {
	cavernIterator.remove();
	continue;
	}
}
else {
	if ( c.site.equals( "z" ) ) {
		cavernIterator.remove();
		continue;
		}
	}
else {
	( c.site.equals( "a" ) ) {
	cavernIterator.remove();
	continue;
	}
}

You can't have several else blocks for the same if. Each else block has to be attached to its own if:

if(a) {
    ...
} else {
    if (b) {
        ...
    }
    else {
        if (c) {
            ...
        }
        else {
            ...
        }
    }
}

Or, with a shorthand for all this, you can have a single-statement block inside the else, so it looks like this:

if (a) {
    ...
}
else if (b) {
    ...
}
else if (c) {
    ...
}
else {
    ...
}

This second one is nearly the same as the first, as it takes advantage of not having to wrap a statement block in braces if your statement block only has single statement, like this:

if (myCondition)
    System.out.println("My condition passed");
else
    System.out.println("My condition did not pass");

Else if should be written this way :

if (...) {
    // Code here
} else if (...) {
    // Code here
} else {
    // Code here
}

Also your cases seem similar

String[] sites = {"x","y","z","a"};
boolean contains = Arrays.stream(sites).anyMatch(c.site::equals);
if (contains) {
    cavernIterator.remove();
    continue;
}

EDIT: Considering site is a string

String site = "x"; // Default value provided
String[] sites = {"x","y","z","a"};
boolean condition = site.equals(c.site) && Arrays.stream(sites).anyMatch(c.site::equals);
if (condition) {
    cavernIterator.remove();
    continue;
}

    if ( site ) {
        if ( c.site.equals( "x" ) ) {
        }
   }

equals

    if(site && c.site.equals("x")){
    }

And your last else is messed up.

Likely look on some Java tutorials because you write the least efficient way possible. This is your code in short:

if (site && (c.site.equals("x") || c.site.equals("y") || c.site.equals("z") || c.site.equals("a"))) {
	cavernIterator.remove();
}