C++ code segments

一.function alias invocation(引用)

#include <iostream>
using namespace std;
void aliasFun(int &, int &);
int main()
{
        int num = 10;
        cout << "Num = " << num << endl;
        int &i = num;
        i = 20;
        cout << "i = " << i << endl;
        cout << "Num = " << num << endl;
        int x = 200;
        int y = 300;
        aliasFun(x,y);
        cout << "x = " << x << ", " << "y = " << y << endl;
        return 0;
}
void aliasFun(int &a,int &b)
{
        a = 4;
        b = 10;
}

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二.type cast
#include <iostream>
using namespace std;
int main(int argc, char **argv)
{
        double d = 3.1415926;
        int i1 = static_cast<int>(d);
        int i2 = (int)d; // old method
        cout << "i1 = " << i1 << endl;
        cout << "i2 = " << i2 << endl;
        return 0;
}

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3.Array definition

int a[4]; // definition
int a[4] = {1,10,2,4} // defination and initialization

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4.pointer
int a = 10;
int *p = &a;
int *p = new int; 
int *p = new int[10]; //dynamic allocate array
delete p;
delete [] p;

void swap(int *num1,int *num2)
{
    int temp = *num1;
    *num1 = *num2;
    *num2 = temp;
}

int main(){
    int x = 10;
    int y = 20;
    swap(&x,&y);
}

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5.character && string
        char *p = "hello very good";
        while(p != "\0")
        {
                cout << *p++;
        }

------------
        char str[10] = "hello!";
        char *p = str;
        for(int i=0;i<6;i++)
        {
                cout << *(p+i);
        }