1 #include <iostream>
2 #include<stdlib.h>
3 #include<string>
4 #include<vector>
5 #include<cstring>
6 #include<bitset>
7
8
9 using namespace std;
10
11 //操作符
12
13 int main()
14 {
15 //算数操作符
16 int i=100;
17 int j=200;
18 cout<<j+i<<endl;
19 cout<<j-i<<endl;
20 cout<<j*i<<endl;
21 cout<<j/i<<endl;
22 cout<<j%i<<endl;
23 int k=-i;
24 cout<<k<<endl;
25 //小心溢出
26 short sv =32767;
27 short ival=5;
28 short l=sv+ival;
29 cout<<l<<endl;
30 //==========================================
31 cout<<"关系和逻辑操作符"<<endl;
32 cout<<"< <= > >= == !="<<endl;
33 cout<<"&& || !"<<endl;
34 int a,b;
35 cout<<"请输入两个整数"<<endl;
36 cin>>a>>b;
37 if(a>b) cout<<a<<"大于"<<b<<endl;
38 if(a<b) cout<<a<<"小于"<<b<<endl;
39 if(a==b) cout<<a<<"等于"<<b<<endl;
40 if(a!=b) cout<<a<<"不等于"<<b<<endl;
41
42 bool x=true;
43 bool y=false;
44 if(x&&y)cout<<12<<endl;
45 if(x||y)cout<<34<<endl;
46 if(!x)cout<<56<<endl;
47
48 cout<<"=========================="<<endl;
49 int val;
50 vector<int> vec;
51 while(cin>>val && val!=42)
52 {
53 //cin>>val;
54 vec.push_back(val);
55 }
56 for(vector<int>::iterator iter=vec.begin();iter!=vec.end();iter++)
57 {
58 cout<<*iter<<endl;
59 }
60 cout<<"=========================="<<endl;
61 char *cp="Hello world";
62 while(cp&&*cp)
63 {
64 cout<<*cp<<endl;
65 ++cp;
66 }
67
68 cout<<"=========================="<<endl;
69 cout<<"位操作符"<<endl;
70
71 unsigned char bits=0227;
72 bits=~bits; //取反
73 cout<<(int)bits<<endl;
74
75 bits=1; //00000001
76 unsigned char result;
77 result=bits<<1; //00000010
78 cout<<(int)result<<endl;
79 result=bits<<2; //00000100
80 cout<<(int)result<<endl;
81 bits=64; //01000000
82 result=bits>>3;//00001000
83 cout<<(int)result<<endl;
84 //&位与 全为1则为1否则为0
85 //|位或 全为0则为0否则为1
86 // ^异或 相同为0不同为1
87 //30个学生合格与否用二进制表示
88 bitset<30> a;
89 a.set(27);//第27位设置为1
90 a.reset(22); //第22位变为0
91
92 cout<<"=========================="<<endl;
93 cout<<"赋值操作符"<<endl;
94 //左操作数必须是非const值
95 //可以连续赋值 右结合性
96 string s1=s2="OK";
97 cout<<"=========================="<<endl;
98 cout<<"自增和自减操作符"<<endl;
99 //++i i++ --i i--
100 int a,b;
101 a=2;
102 b=++a; //3
103 b=a++; //2
104 cout<<b<<endl;
105 cout<<"=========================="<<endl;
106 cout<<"箭头操作符"<<endl;
107 //(*p).foo() p->foo()
108 vector<string*> v;
109 string str1;
110 cout<<"enter input:"<<endl;
111 while(cin>>str1)
112 {
113 string *p=new string;
114 *p=str1;
115 v.push_back(p);
116 }
117 cout<<"output"<<endl;
118 vector<string*>::iterator it=v.begin();
119 while(it!=v.end() )
120 {
121 cout<<**it++<<"=="<<(*it)->size()<<endl;
122 }
123 it=v.begin();
124 while(it!=v.end())
125 {
126 delete[] *it;
127 it++;
128 }
129
130 return 0;
131 }
运算符优先级：https://baike.baidu.com/item/%E8%BF%90%E7%AE%97%E7%AC%A6%E4%BC%98%E5%85%88%E7%BA%A7/4752611?fr=aladdin