Net基础篇_学习笔记_第九天_数组_三个练习

练习一：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _数组练习01
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = null;
            string[] names = { "老杨","老李","老赵","老孙","老沈"};
            for (int i = 0; i < names.Length; i++)
            {
                str += names[i] + "|";
            }
            Console.WriteLine(str);
            Console.ReadKey();
        }
    }
}

优化为：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _数组练习01
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = null;
            string[] names = { "老杨","老李","老赵","老孙","老沈"};
            for (int i = 0; i < names.Length-1; i++)
            {
                str += names[i] + "|";
            }
            Console.WriteLine(str+names[names.Length-1]);
            Console.ReadKey();
        }
    }
}

 练习二：如遇正数，将这个位置元素的值加1，如遇负数，将这个位置元素的值减1，如遇0，则不变。

int nums={0，5，-8，-41，5，94，-1，-22}；

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _数组练习01
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] nums = { 66,58,841,-556,-121,-541,55};
            for (int i = 0; i < nums.Length; i++)
            {
                if (nums[i] > 0)
                {
                    nums[i] += 1;
                }
                else if (nums[i] < 0)
                {
                    nums[i] -= 1;
                }
            }
            for (int i = 0; i < nums.Length; i++)
            {
                Console.WriteLine(nums[i]);
            } 
            Console.ReadKey();
        }
    }
}

 联系三：将一个字符串数组的元素顺序进行反转

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _数组练习01
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] names  = { "a", "b", "c" ,"d"};
            for (int i = 0; i <names.Length/2; i++)
            {
                //交换两个变量最简单的方式就是声明第三方的一个变量。
                string _temp = names[i];
                names[i] = names[names.Length - 1 - i];
                names[names.Length - 1 - i] = _temp;
            }
            for (int i = 0; i < names.Length; i++)
            {
                Console.WriteLine(names[i]);
            }
            Console.ReadKey();
        }
    }
}