一些lambda的基础知识,例子都非常的简单.
class Program
{
delegate int 乘法(int i);
static void Main(string[] args)
{
//显示数组中大于5的();
//找出字符串中包含o的字符串();
//显示年龄大于20岁的人且计数();
//用枚举器显示年龄大于20岁的();
//委托乘法();
//显示字符串以J开头的();
//整数数组排序();
//按年龄大小排序();
//取出姓的唯一值并打印出详细清单();
Console.ReadLine();
}
private static void 显示年龄大于20岁的人且计数()
{
var names = new[]{
new {Name="jack",Age=20},
new {Name="rose",Age=10},
new {Name="tom",Age=30},
new {Name="jerry",Age=40},
new {Name="Black",Age=50},
};
var output = names.Where(p => p.Age > 20);
foreach (var item in output)
{
Console.WriteLine("名字是{0},年龄是{1}", item.Name, item.Age);
}
Console.WriteLine("年龄大于20岁的一共有:{0}", output.Count());
}
private static void 取出姓的唯一值并打印出详细清单()
{
var names = new[]{
new {Name="jack 盖茨",Age=20},
new {Name="rose 吴",Age=10},
new {Name="tom 邓",Age=30},
new {Name="jerry 盖茨",Age=40},
new {Name="Black 吴",Age=50},
};
var output = names.GroupBy(p => p.Name.Split(' ')[1]);
foreach (var item in output)
{
Console.WriteLine(item.Key);
foreach (var 详细 in item)
{
Console.WriteLine(" " + 详细);
}
}
}
private static void 按年龄大小排序()
{
var names = new[]{
new {Name="jack",Age=20},
new {Name="rose",Age=10},
new {Name="tom",Age=30},
new {Name="jerry",Age=40},
new {Name="Black",Age=50},
};
var output = names.OrderBy(p => p.Age).Select(p => p);
foreach (var item in output)
{
Console.WriteLine("名字是{0},年龄是{1}", item.Name, item.Age);
}
}
private static void 整数数组排序()
{
int[] arr = { 5, 8, 9, 1, 4, 2, 3 };
var output = arr.OrderBy(p => p);
foreach (var item in output)
{
Console.WriteLine(item);
}
}
private static void 显示字符串以J开头的()
{
string[] str = { "tom", "jerry", "jack", "rose" };
var output = str.Select(p => p).Where(p => p.StartsWith("j"));
foreach (var item in output)
{
Console.WriteLine(item);
}
}
private static void 委托乘法()
{
乘法 x2;
x2 = p => p * 2;
for (int i = 0; i < 10; i++)
{
Console.WriteLine(x2(i));
}
x2 = p => p * p;
for (int i = 0; i < 10; i++)
{
Console.WriteLine(x2(i));
}
}
private static void 用枚举器显示年龄大于20岁的()
{
var names = new[]{
new {Name="jack",Age=20},
new {Name="rose",Age=10},
new {Name="tom",Age=30},
new {Name="jerry",Age=40},
new {Name="Black",Age=50},
};
var ie = names.Where(p => p.Age > 20).Select(p => p);
var output = ie.GetEnumerator();
while (output.MoveNext())
{
Console.WriteLine("名字是{0},年龄是{1}", output.Current.Name, output.Current.Age);
}
}
private static void 找出字符串中包含o的字符串()
{
string[] str = { "tom", "jerry", "jack", "rose" };
var output = str.Select(p => p).Where(p => p.ToCharArray().Contains('o'));
foreach (var item in output)
{
Console.WriteLine(item);
}
}
private static void 显示数组中大于5的()
{
int[] arr = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
var output = arr.Select(p => p).Where(p => p > 5);
foreach (var item in output)
{
Console.WriteLine(item);
}
}
}
