From 19903ae3536255dfa2778846275267605cee9f7e Mon Sep 17 00:00:00 2001
From: Oskar <open7software@gmail.com>
Date: Sun, 18 Aug 2024 21:02:35 +0200
Subject: more exercises, one unfinished

---
 4p13.cpp            | 23 +++++++++++++++++++++++
 4p14.cpp            | 21 +++++++++++++++++++++
 4p15.cpp            | 26 ++++++++++++++++++++++++++
 4p16.cpp            | 29 +++++++++++++++++++++++++++++
 4p17.cpp            | 14 ++++++++++++++
 4p18.cpp            | 20 ++++++++++++++++++++
 4p19.cpp            | 19 +++++++++++++++++++
 increment-tests.cpp | 19 +++++++++++++++++++
 8 files changed, 171 insertions(+)
 create mode 100644 4p13.cpp
 create mode 100644 4p14.cpp
 create mode 100644 4p15.cpp
 create mode 100644 4p16.cpp
 create mode 100644 4p17.cpp
 create mode 100644 4p18.cpp
 create mode 100644 4p19.cpp
 create mode 100644 increment-tests.cpp

diff --git a/4p13.cpp b/4p13.cpp
new file mode 100644
index 0000000..b5cfdf1
--- /dev/null
+++ b/4p13.cpp
@@ -0,0 +1,23 @@
+#include <iostream>
+
+/*
+ *
+ * 4.13
+ *
+ * 
+ */
+
+int main () {
+	
+	
+	int i1;
+	int i2;
+	double d1;
+	double d2;
+	double threepointfive = 3.5; // made a variable for 3.5 to avoid compiler errors
+	d1 = i1 = threepointfive; // i == 3, d == 3
+	i2 = d2 = threepointfive; // d == 3.5, i == 3
+	std::cout << d1 << " <-d1(3) (3)i1-> " << i1 << std::endl;
+	std::cout << d2 << " <-d2(3.5) (3)i2-> " << i2 << std::endl;
+	return 0;
+}
diff --git a/4p14.cpp b/4p14.cpp
new file mode 100644
index 0000000..84fe963
--- /dev/null
+++ b/4p14.cpp
@@ -0,0 +1,21 @@
+#include <iostream>
+
+/*
+ *
+ * 4.14
+ *
+ *
+ */
+
+int main () {
+
+	int i = 0;
+
+	//if(42 = i) {} Not valid, error
+	int ifs2 = i = 42;
+	if(ifs2) { // evaluates as true because nonZero == true
+		std::cout << "..." << std::endl;
+	}
+	
+	return 0;
+}
diff --git a/4p15.cpp b/4p15.cpp
new file mode 100644
index 0000000..7ac66d5
--- /dev/null
+++ b/4p15.cpp
@@ -0,0 +1,26 @@
+#include <iostream>
+
+/*
+ *
+ * 4.15
+ *
+ *
+ */
+
+int main () {
+
+	double dval;
+	int ival;
+	int *pi;
+	/*
+	ival = 0;
+	dval = 0;
+	pi = 0;
+
+	I don't really see a reason not to do it this way but both of these examples work
+	*/
+	ival = dval = 0;
+	pi = 0;
+	std::cout << dval << ival << pi << std::endl;
+	return 0;
+}
diff --git a/4p16.cpp b/4p16.cpp
new file mode 100644
index 0000000..5205446
--- /dev/null
+++ b/4p16.cpp
@@ -0,0 +1,29 @@
+#include <iostream>
+
+/*
+ *
+ * 4.16
+ *
+ * Added a mockup getPtr function to demonstrate
+ */
+
+int *getPtr(int *f) {
+	
+	return f;
+}
+
+int main () {
+	
+	int f;
+	int *p = nullptr;
+	if ((p = getPtr(&f)) != 0) {
+		std::cout << "not nullptr" << std::endl;
+	}
+
+	int i = 1024;
+	if (i == 1024) {
+		std::cout << "i: 1024" << std::endl;
+	}
+	
+	return 0;
+}
diff --git a/4p17.cpp b/4p17.cpp
new file mode 100644
index 0000000..63459d8
--- /dev/null
+++ b/4p17.cpp
@@ -0,0 +1,14 @@
+
+/*
+ *
+ * 4.17
+ *
+ *
+ */
+
+int main () {
+
+	// Prefix increments will increment the object by 1 and return the incremented object as result.
+	// Postfix increment will increment the object by 1 but return a copy of the object before being incremented.
+	return 0;
+}
diff --git a/4p18.cpp b/4p18.cpp
new file mode 100644
index 0000000..0788e51
--- /dev/null
+++ b/4p18.cpp
@@ -0,0 +1,20 @@
+
+/*
+ *
+ * 4.18
+ *
+ *
+ */
+
+int main () {
+	/*
+	auto pbeg = v.begin();
+	while (pbeg != v.end() && *beg >= 0)
+		cout << *pbeg++ << endl;
+	*/
+
+	// It would increment pbeg by 1 and then dereference and print.
+	// This would mean that the first element in the vector is not printed
+	// This would also mean dereferencing whatever is at v.end() which is not a good idea.
+	return 0;
+}
diff --git a/4p19.cpp b/4p19.cpp
new file mode 100644
index 0000000..ab94f28
--- /dev/null
+++ b/4p19.cpp
@@ -0,0 +1,19 @@
+#include <iostream>
+#include <vector>
+
+/*
+ *
+ * 4.19
+ *
+ *
+ */
+
+int main () {
+
+	int *ptr = nullptr;
+	int aa = 12374;
+	int ival = 0;
+	ptr = &aa;
+	vector<int> vec;
+	return 0;
+}
diff --git a/increment-tests.cpp b/increment-tests.cpp
new file mode 100644
index 0000000..d5b5665
--- /dev/null
+++ b/increment-tests.cpp
@@ -0,0 +1,19 @@
+#include <iostream>
+
+/*
+ *
+ * 
+ *
+ *
+ */
+
+int main () {
+
+	int i = 0;
+	int j = 0;
+	int k = 0;
+	j = ++i;
+	k = i++;
+	std::cout << i << " " << j << " " << k << std::endl;
+	return 0;
+}
-- 
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