public void Execute()
{
//
// Take拡張メソッドは、シーケンスの先頭から指定された件数分を返すメソッド。
//
// ・シーケンスの要素数より多い数を指定した場合、そのシーケンス全てが返る.
// ・0以下の値を指定した場合、空のシーケンスが返る.
//
var names = new[] {"gsf_zero1", "gsf_zero2", "gsf_zero3", "gsf_zero4", "gsf_zero5"};
Output.WriteLine("================ Take ======================");
var top3 = names.Take(3);
foreach (var item in top3)
{
Output.WriteLine(item);
}
foreach (var item in names.Take(20))
{
Output.WriteLine(item);
}
Output.WriteLine("0以下の数値を指定: COUNT={0}", names.Take(-1).Count());
//
// TakeWhile拡張メソッドは、指定された条件が満たされる間シーケンスから要素を抽出し
// 返すメソッド。
//
Output.WriteLine("================ TakeWhile ======================");
var lessThan4 = names.TakeWhile(name => int.Parse(name.Last().ToString()) <= 4);
foreach (var item in lessThan4)
{
Output.WriteLine(item);
}
}
public static void Test(Assert assert)
{
assert.Expect(8);
// TEST
var numbers = new[] { 1, 3, 5, 7, 9 };
var firstTwo = numbers.Take(2).ToArray();
assert.DeepEqual(firstTwo, new[] { 1, 3 }, "Take() the first two array elements");
// TEST
var lastThree = numbers.TakeFromLast(3).ToArray();
assert.DeepEqual(lastThree, new[] { 5, 7, 9 }, "TakeFromLast() the last three array elements");
// TEST
var exceptTwoLast = numbers.TakeExceptLast(2).ToArray();
assert.DeepEqual(exceptTwoLast, new[] { 1, 3, 5 }, "TakeExceptLast() the first array elements except the last two");
// TEST
var takeWhileLessTwo = numbers.TakeWhile((number) => number < 2).ToArray();
assert.DeepEqual(takeWhileLessTwo, new[] { 1 }, "TakeWhile() less two");
// TEST
var takeWhileSome = numbers.TakeWhile((number, index) => number - index <= 4).ToArray();
assert.DeepEqual(takeWhileSome, new[] { 1, 3, 5, 7 }, "TakeWhile() by value and index");
// TEST
var skipThree = numbers.Skip(3).ToArray();
assert.DeepEqual(skipThree, new[] { 7, 9 }, "Skip() the first three");
// TEST
var skipWhileLessNine = numbers.SkipWhile(number => number < 9).ToArray();
assert.DeepEqual(skipWhileLessNine, new[] { 9 }, "SkipWhile() less then 9");
// TEST
var skipWhileSome = numbers.SkipWhile((number, index) => number <= 3 && index < 2).ToArray();
assert.DeepEqual(skipWhileSome, new[] { 5, 7, 9 }, "SkipWhile() by value and index");
}
