语句，分支

using System.Formats.Asn1;

namespace MyFirstConsoleApp
{
internal class Program
{
static void Main(string[] args)
{
TryAnIF();
TryAnIfElse();
TrySomeLoops();
}
///
/// 要点
///
///
/***
*不要忘记所有语句都要以一个分号结束
*行首使用两个斜线为代码增加注释
*声明变量时要提供一个类型，后面是一个名字
*大多数情况下，可以有额外空白符
*if/else、while、do和for都要测试条件
***/
private static void TryAnIF()
{
int someValue = 4;
string name = “Bobbo Jr.”;
if ((someValue == 3) && (name == “Joe”))
{
Console.WriteLine(“x is 3 and the name is Joe”);
}
Console.WriteLine(“this line runs no matter what”);
}

    private static void TryAnIfElse()
    {
        int x = 5;
        if (x == 10)
        {
            Console.WriteLine("x must be 10");
        }
        else
        {
            Console.WriteLine("x isn't 10");
        }
    }

    private static void TrySomeLoops()
    {
        int count = 0;

        while (count < 10)
        {
            count = count + 1;
        }
        for (int i = 0; i < 5; i++)
        {
            count = count - 1;
        }
        Console.WriteLine("The answer is " + count);
    }


    private static int area;
    private static int height;
    private static int width;

    static void Main(string[] args)
    {
        OperatorExamples();
    }

    private static void OperatorExamples()
    {
        Console.WriteLine(area);

        while (area < 20)
        {
            height++;
            area = width * height;

        }
        do
        {
            width--;
            area = width * height;
        } while (area > 25);
        //This statement declares a variable and sets it to 3
        int width = 3;
        //The == operator increments a variable (adds 1 to 3)
        width++;

        //Declare two more int variables to hold numbers and
        //use the + and * operators to add and multiple values
        int height = 2 + 4;
        int area = width * height;
        Console.WriteLine(area);

        //The next two statements declare string variables
        //and use + to concatenate them (join them together)
        string result = "The area";
        result = result + " is " + area;
        Console.WriteLine(result);

        //A Boolean variable is either true or false
        bool truthValue = true;
        Console.WriteLine(truthValue);

        //“if”语句做决策
        int someValue = 10;
        string message = "";
        if (someValue == 24)
        {
            message = "Yes,it' 24!";
        }

        //if/else语句在条件不为真时也会做些事情
        if (someValue == 24)
        {
            message = "Yes,it' 24!";
        }
        else
        {
            message = "The value wasn't 24.";
        }

        //while循环就是当条件为true时循环执行语句
        int x = 10;
        while (x > 5)
        {

        }

        //do/while循环先运行语句再检查条件
        do
        {

        } while (x > 5);

        //for循环在每次循环后运行一个语句
        for (int i = 0; i < 8; i = 1 + 2)
        {

        }

        LOOP#1
        int count = 5;
        while (count > 0)
        {
            count = count * 3;
            count = count * -1;
        }

        LOOP #2
        int j = 2;
        for (int i = 1; i < 100; i = i * 2)
        {
            j = j - 1;
            while (j < 25) //执行7次
            {
                //下一个语句会执行多少次？
                j = j + 5; //执行6次
            }
        }

        //LOOP #3
        int p = 2;
        for (int q = 2; q < 32; q = q * 2)
        {
            while (p < q) //执行10次
            {
                p = p * 2;//执行3次
            }
            q = p - q;
        }

        LOOP #4
        int i = 0;
        int count = 2;
        while (i == 0)//死循环
        {
            count = count * 3;
            count = count * -1;
        }

    }
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153

}
}