Added references examples

Author: eloyekunle

absoluteDifference.cpp

@@ -0,0 +1,19 @@
+#include<iostream>
+using namespace std;
+
+int main() {
+	//declare the two variables
+	int n, m;
+	//read them in from standard input
+	cin >> n >> m;
+	//calculate the difference
+	int diff = n - m;
+
+	if (diff < 0) {
+		diff = diff*(-1);
+	}
+
+	cout << diff << endl;
+
+	return 0;
+}

references/1.cpp

@@ -0,0 +1,30 @@
+#include <iostream>
+
+using namespace std;
+
+int main() {
+	int x = 3;
+	cout << "x is: " << x << "; &x is: " << &x << endl;
+	int &xRef = x;
+	cout << "xRef is: " << xRef << endl;
+	int *hell = &xRef;
+	cout << "hell is: " << hell << "; *hell is: " << *hell << "; &hell is: " << &hell << endl;
+	xRef = 10;
+	cout << "x is: " << x << "; xRef is: " << xRef << endl;
+	cout << "&xRef is: " << &xRef << endl;
+
+	const int &unnamedRef2 = 5;
+	cout << "unnamedRef2 is: " << unnamedRef2 << endl;
+
+	int *intP;
+	cout << "intP is: " << intP << "; *intP is: " << *intP << endl;
+	
+	int *&ptrRef = intP;
+	cout << "intP is: " << intP << "; *intP is: " << *intP << "; &intP is: " << &intP << "; ptrRef is: " << ptrRef << "; *ptrRef is: " << *ptrRef << "; &ptrRef is: " << &ptrRef << endl;
+	
+	ptrRef = new int;
+	cout << "intP is: " << intP << "; *intP is: " << *intP << "; &intP is: " << &intP << "; ptrRef is: " << ptrRef << "; *ptrRef is: " << *ptrRef << "; &ptrRef is: " << &ptrRef << endl;
+	
+	*ptrRef = 5;
+	cout << "intP is: " << intP << "; *intP is: " << *intP << "; &intP is: " << &intP << "; ptrRef is: " << ptrRef << "; *ptrRef is: " << *ptrRef << "; &ptrRef is: " << &ptrRef << endl;
+}

references/separateOddsAndEvens.cpp

@@ -0,0 +1,50 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void separateOddsAndEvens(const vector<int>& arr, vector<int>& odds, vector<int>& evens);
+void printVector(const vector<int>& vec);
+
+int main() {
+	vector<int> arrUnsplit = {1,2,3,4,5,6,7,8,9,10};
+	vector<int> odds, evens;
+	cout << "main array is: " << endl;
+	printVector(arrUnsplit);
+	separateOddsAndEvens(arrUnsplit, odds, evens);
+	cout << "odds is: " << endl;
+	printVector(odds);
+	cout << "evens is: " << endl;
+	printVector(evens);
+
+	return 0;
+}
+
+void separateOddsAndEvens(const vector<int>& arr, vector<int>& odds, vector<int>& evens) {
+	int numodds = 0, numevens = 0;
+	for(auto& i : arr) {
+		if(i % 2 == 1) {
+			numodds++;
+		} else {
+			numevens++;
+		}
+	}
+
+	odds.reserve(numodds);
+	evens.reserve(numevens);
+	for(auto& i : arr) {
+		if(i % 2 == 1) {
+			odds.push_back(i);
+		} else {
+			evens.push_back(i);
+		}
+	}
+}
+
+void printVector(const vector<int>& vec) {
+	cout << "[";
+	for(auto& i : vec) {
+		cout << i << ", ";
+	}
+	cout << "]" << endl;
+}

references/swap.cpp

@@ -0,0 +1,29 @@
+#include <iostream>
+
+using namespace std;
+void swap(int first, int second);
+void swapRef(int &firstRef, int &secondRef);
+
+int main() {
+	int first = 5, second = 15;
+	swap(first, second);
+	cout << "first is now: " << first << "; and second is now: " << second << endl;
+	swapRef(first, second);
+	cout << "first is now: " << first << "; and second is now: " << second << endl;
+
+	return 0;
+}
+
+void swap(int first, int second) {
+	int temp = first;
+	first = second;
+	second = temp;
+	cout << "in 'swap' function, first is: " << first << "; and second is: " << second << endl;
+}
+
+void swapRef(int &firstRef, int &secondRef) {
+	int temp = firstRef;
+	firstRef = secondRef;
+	secondRef = temp;
+	cout << "in 'swapRef' function, first is: " << firstRef << "; and second is: " << secondRef << endl;
+}