Initial commit

test/aggregation/set.dart

@@ -0,0 +1,30 @@
+void main() {
+  foo3();
+}
+
+void foo1() {
+  Set<int> numSet = {1, 9, 9, 4};
+  print(numSet);
+}
+
+void foo2() {
+  Set<int> numSet = {1, 9, 4};
+  numSet.add(10);
+  numSet.remove(9);
+  print(numSet);
+}
+
+void foo3() {
+  Set<int> a = {1, 9, 4};
+  Set<int> b = {1, 9, 3};
+  print(a.difference(b));// 差集
+  print(a.union(b)); // 并集
+  print(a.intersection(b)); // 交集
+}
+
+void foo4() {
+  Set<int> numSet = {1, 9, 4};
+  for(int value in numSet){
+    print("元素值:$value");
+  }
+}