#include iostreamusing namespace std;int main () {// declare simple variablesinti;double d;// declare reference variables

// C++标准输出流#include iostreamusing namespace std;int main() {char str[] = Hello C++;

#include iostreamusing namespace std;int sum(int a, int b = 20) {int result;result = a + b;return (result);

#include iostreamusing namespace std;void swap(int x, int y) {int temp;temp = x; /* save the value of x */

#include iostream#include ctimeusing namespace std;int main() {// current date/time based on current system

#include iostream#include ctime#include cstdlibusing namespace std;int main () {

#include iostreamusing namespace std;int main () {// number definition:shorts;inti;longl;floatf;

#include iostreamusing namespace std;// function definition to swap the values.void swap(int x, int y) {

#include iostream#include ctimeusing namespace std;// function to generate and retrun random numbers.

#include iostreamusing namespace std;double getAverage(int arr[], int size) {int i, sum = 0;double avg;

#include iostreamusing namespace std;int main () {// an array with 5 elements.double balance[5] = {1000.0, 2.0, 3.4, 17.0, 50.0};

#include iostreamusing namespace std;#include iomanipusing std::setw;int main () {int n[ 10 ];// n is an array of 10 integers

#include iostreamusing namespace std;int main () {char greeting[6] = {H, e, l, l, o, \\0};

#include iostream#include cstringusing namespace std;int main () {char str1[10] = Hello;

// #include iostreamusing namespace std;int main () {intvar1;char var2[10];cout Address of var1 variable: ;

#include iostreamusing namespace std;int main () {intvar = 20;// actual variable declaration.

#include iostreamusing namespace std;int main () {int*ptr = NULL;cout The value of ptr is ptr ;

#include iostream#include ctimeusing namespace std;// function to generate and retrun random numbers.

#include iostream#include ctimeusing namespace std;int main() {// current date/time based on current system

#include iostreamusing namespace std;// function declarationvoid swap(int x, int y);