commaOperatorOtherValidOperation.ts(18,5): error TS2454: Variable 'x' is used before being assigned.
commaOperatorOtherValidOperation.ts(18,8): error TS2454: Variable 'y' is used before being assigned.
commaOperatorOtherValidOperation.ts(19,23): error TS2454: Variable 'y' is used before being assigned.
commaOperatorOtherValidOperation.ts(19,26): error TS2454: Variable 'x' is used before being assigned.


==== commaOperatorOtherValidOperation.ts (4 errors) ====
    //Comma operator in for loop
    for (var i = 0, j = 10; i < j; i++, j--)
    {
    }
    
    //Comma operator in function arguments and return
    function foo(x: number, y: string)
    {
        return x, y;
    }
    var resultIsString = foo(1, "123");
    
    //TypeParameters
    function foo1<T1, T2>()
    {
        var x: T1;
        var y: T2;
        x, y;
        ~
!!! error TS2454: Variable 'x' is used before being assigned.
           ~
!!! error TS2454: Variable 'y' is used before being assigned.
        var resultIsT1 = (y, x);
                          ~
!!! error TS2454: Variable 'y' is used before being assigned.
                             ~
!!! error TS2454: Variable 'x' is used before being assigned.
    }
    