Finish: 02-slices - 切片操作

stage04-composite-types/02-slices/main.go

@@ -6,10 +6,10 @@ func exercise1() []int {
 	fmt.Println("=== 练习1：切片声明与初始化 ===")
 
 	// 创建一个长度为3的int切片，初始值为[1, 2, 3]
-	s := make([]int, ____)
-	s[0], s[1], s[2] = ____, ____, ____
+	s := make([]int, 3)
+	s[0], s[1], s[2] = 1, 2, 3
 
-	return ____
+	return s
 }
 
 func exercise2() int {
@@ -17,10 +17,10 @@ func exercise2() int {
 
 	// 向切片中添加元素并返回新长度
 	fruits := []string{"苹果", "香蕉"}
-	fruits = append(fruits, ____)
-	fruits = append(fruits, ____, ____)
+	fruits = append(fruits, "梨子")
+	fruits = append(fruits, "蓝莓", "草莓")
 
-	return ____(fruits)
+	return len(fruits)
 }
 
 func exercise3() []int {
@@ -29,14 +29,14 @@ func exercise3() []int {
 	// 从切片中提取子切片
 	numbers := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
 
-	// 提取索引2到6（不包含6）
-	sub1 := numbers[____:____]
+	// 提取索引2到5（不包含5）
+	sub1 := numbers[2:5]
 
 	// 提取前5个元素
-	sub2 := numbers[:____]
+	sub2 := numbers[:5]
 
 	// 提取从第5个开始到末尾
-	sub3 := numbers[____:]
+	sub3 := numbers[4:]
 
 	fmt.Printf("子切片1: %v\n", sub1)
 	fmt.Printf("子切片2: %v\n", sub2)
@@ -50,13 +50,13 @@ func exercise4() int {
 
 	// 修改原始切片，观察使用copy复制的切片是否受影响
 	s1 := []int{1, 2, 3}
-	s2 := make([]int, ____(s1))
+	s2 := make([]int, len(s1))
 
-	copy(____, s1)
+	copy(s2, s1)
 
 	s1[0] = 99
 
-	return ____
+	return s2[0]
 }
 
 func exercise5() []int {
@@ -65,19 +65,19 @@ func exercise5() []int {
 	// 创建一个新切片，包含原切片中所有偶数
 	numbers := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
 
-	var evens ____
+	var evens []int
 
-	for _, num := range ____ {
-		if num%2 == ____ {
-			evens = append(____, num)
+	for _, num := range numbers {
+		if num%2 == 0 {
+			evens = append(evens, num)
 		}
 	}
 
-	return ____
+	return evens
 }
 
 func main() {
-	fmt.Println("=== 切片 练习 ===\n")
+	fmt.Println("=== 切片 练习 ===")
 
 	result1 := exercise1()
 	fmt.Printf("练习1结果: %v\n", result1)