You could, of course, “make the outer value mutable” via a trick: public void test() { String[] x = new String[1]; List<String> list = Arrays.asList(“a”, “b”, “c”, “d”); list.forEach(n -> { if (n.equals(“d”)) x[0] = “match the value”; }); } Get ready for a beating by the functional purist on the team, though. Much nicer, … Read more
It’s not possible to loop backwards using the for each loop syntax. As an alternative you can use a For i = a To 1 Step -1 loop: Sub reverseForEach() Dim i As Long, rng As Range Set rng = ActiveSheet.Range(“A1:B2”) For i = rng.Cells.Count To 1 Step -1 Debug.Print rng.item(i).Address ‘ Or shorthand rng(i) … Read more
I think the 2009 paper “Pairs do not make good ranges” by Alisdair Meredith is at least part of the answer. Basically, many algorithms return pairs of iterators that are actually not guaranteed to be valid ranges. It seems they removed the support for pair<iterator,iterator> from the for-range loop for this reason. However, the proposed … Read more
This should work: DataTable dtTable; MySQLProcessor.DTTable(mysqlCommand, out dtTable); // On all tables’ rows foreach (DataRow dtRow in dtTable.Rows) { // On all tables’ columns foreach(DataColumn dc in dtTable.Columns) { var field1 = dtRow[dc].ToString(); } }
If you are using foreach inside a function and you are expecting an array or a Traversable object you can type hint that function with: function myFunction(array $a) function myFunction(Traversable) If you are not using foreach inside a function or you are expecting both you can simply use this construct to check if you can … Read more
You could try this: List<Int32> copy = new List<Int32>(original); or if you’re using C# 3 and .NET 3.5, with Linq, you can do this: List<Int32> copy = original.ToList(); I see that this answer is still getting upvotes. Well, here’s a secret for ya: the above answer is still using a foreach. Please don’t upvote this … Read more
The loop is equivalent to: for(int j = 0; j < number.length; j++) { int i = number[j]; … } where j is an internally generated reference that does not conflict with normal user identifiers.
The Standard is your friend, see [stmt.ranged]/1 For a range-based for statement of the form for ( for-range-declaration : expression ) statement let range-init be equivalent to the expression surrounded by parentheses ( expression ) and for a range-based for statement of the form for ( for-range-declaration : braced-init-list ) statement let range-init be equivalent … Read more
There are many ways, one is to use a counter: $i = 0; foreach ($arr as $k => $v) { /* Do stuff */ if (++$i == 2) break; } Other way would be to slice the first 2 elements, this isn’t as efficient though: foreach (array_slice($arr, 0, 2) as $k => $v) { /* … Read more
What Jason said is totally correct in his answer but I thought I would give it a shot, to better clarify. This is actually a classic closure problem. Typically it would look something like: for(var i = 0; i < 10; i++){ setTimeout(function(){ console.log(i); },i * 1000) } The novice would expect the console to … Read more