查找最接近给定数字的数组中的数字位置

def find_closest_number(arr, target):
    min_diff = float('inf')  # 初始化最小差值为正无穷大
    closest_num = None  # 初始化最接近的数字为None

    for num in arr:
        diff = abs(num - target)  # 计算差值的绝对值
        if diff < min_diff:
            min_diff = diff
            closest_num = num

    return arr.index(closest_num)  # 返回最接近数字的位置

# 示例用法
arr = [1, 3, 5, 7, 9]
target = 6
closest_index = find_closest_number(arr, target)
print("最接近数字的位置是:", closest_index)