Swift 数组的相关操作示范

1. 创建一个数组

var fruits = ["apple", "banana", "orange", "grape", "pear"]

2. 访问数组中的元素

print(fruits[0]) // apple
print(fruits[3]) // grape

3. 添加新的元素到数组中

fruits.append("kiwi")
print(fruits) // ["apple", "banana", "orange", "grape", "pear", "kiwi"]

4. 插入元素到数组中的指定位置

fruits.insert("watermelon", at: 2)
print(fruits) // ["apple", "banana", "watermelon", "orange", "grape", "pear", "kiwi"]

5. 删除数组中指定位置的元素

fruits.remove(at: 3)
print(fruits) // ["apple", "banana", "watermelon", "grape", "pear", "kiwi"]

6. 修改数组中的元素

fruits[1] = "cherry"
print(fruits) // ["apple", "cherry", "watermelon", "grape", "pear", "kiwi"]

7. 数组长度

print(fruits.count) // 6

8. 遍历数组中的所有元素

for fruit in fruits {
    print(fruit)
}

// 输出：
// apple
// cherry
// watermelon
// grape
// pear
// kiwi

9. 判断数组是否为空

if fruits.isEmpty {
    print("The array is empty.")
} else {
    print("The array has \(fruits.count) elements.")
}

10. 按照字母顺序排序数组

fruits.sort()
print(fruits) // ["apple", "cherry", "grape", "kiwi", "pear", "watermelon"]