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flow_control.cpp
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Sat, Aug 24, 04:13

flow_control.cpp
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#include <cassert>
#include <cmath>
#include <cstdlib>
#include <iostream>
//////////////////////////////////////////////////////////////////////
void Statement() {}
//////////////////////////////////////////////////////////////////////
void if_syntax() {
int p, q;
if (p > q) {
/*
Statement1;
Statement2;
*/
}
}
//////////////////////////////////////////////////////////////////////
void if_short_syntax() {
int p, q;
if (p > q)
Statement();
}
//////////////////////////////////////////////////////////////////////
void if_example1() {
double x = -2.0;
if (x < 0.0) {
x = 0.0;
}
}
//////////////////////////////////////////////////////////////////////
void if_else_example() {
int i;
double y;
if (i > 0) {
y = 2.0;
} else {
// When i <= 0
y = 10.0;
}
}
//////////////////////////////////////////////////////////////////////
void multiple_if_example() {
int i;
double y;
if (i > 100) {
y = 2.0;
} else if (i < 0) {
y = 10.0;
} else {
// When 0 <= i <= 100
y = 5.0;
}
}
//////////////////////////////////////////////////////////////////////
void nested_if_example() {
double x, z, p, q;
double y;
if (x > z) {
if (p > q) {
// Both conditions have been met
y = 10.0;
}
}
}
//////////////////////////////////////////////////////////////////////
void switch_statement() {
int i;
switch (i) {
case 1:
std::cout << "i = 1\n";
case 20:
// The following line is executed also in case i == 1!
std::cout << "i = 1 or i = 20\n";
break;
case 30:
std::cout << "i = 30\n";
break;
default:
std::cout << "i is not 1, 20 nor 30\n";
}
}
//////////////////////////////////////////////////////////////////////
void bool_condition() {
bool flag = true;
if (flag) {
std::cout << "This will be printed\n";
} else {
// flag is false
std::cout << "This won't be printed\n";
}
}
//////////////////////////////////////////////////////////////////////
void and_condition() {
double x, z, p, q;
double y;
if ((x > z) && (p > q)) {
// Both conditions have been met
y = 10.0;
}
}
//////////////////////////////////////////////////////////////////////
void negation_condition() {
int i;
bool flag = false;
if (!flag) {
// !flag is true when flag is false
i += 2;
}
}
//////////////////////////////////////////////////////////////////////
void or_condition() {
double p, q;
double i;
double y;
if ((y > q) || (i != 1)) {
// One or both conditions have been met
y = 10.0;
} else {
// Neither condition has been met:
// y<=q and i==1
y = -10.0;
}
}
//////////////////////////////////////////////////////////////////////
void while_statement() {
double x = 10.0;
int count = 0;
while (x > 1.0) {
// This loop will execute while x > 1, so if the
// value of x does not decrease then it will not
// terminate.
x *= 0.5;
std::cout << "x = " << x << ", count = " << count << "\n";
count++;
std::cout << "Reached bottom of while loop\n";
}
// Here we know the guard (x > 1.0) has broken.
// This means that after the loop, x <= 1.0
std::cout << "x = " << x << ", count = " << count << "\n";
}
//////////////////////////////////////////////////////////////////////
void do_while() {
double x = .8;
int count = 0;
do {
x *= 0.5;
std::cout << "x = " << x << ", count = " << count << "\n";
count++;
std::cout << "Reached bottom of while loop\n";
} while (x > 1.0);
std::cout << "count = " << count << "\n";
}
//////////////////////////////////////////////////////////////////////
void for_loops() {
for (int i = 0; i < 5; i++) {
for (int j = 5; j > i; j--) {
std::cout << "i = " << i << " j = " << j << "\n";
}
}
}
//////////////////////////////////////////////////////////////////////
void scalar_product() {
double vector1[2], vector2[2];
// The indices of an array start at 0, not at 1!
vector1[0] = 0.5;
vector1[1] = -2.3;
vector2[0] = 34.2;
vector2[1] = 0.015;
double scalar_product = 0.0;
for (int i = 0; i < 2; i++) {
scalar_product += vector1[i] * vector2[i];
}
}
//////////////////////////////////////////////////////////////////////
void tip1() {
double x = 2.0;
for (int i = 0; i < 5; i++)
;
{
x *= 2.0;
std::cout << "x = " << x << "\n";
}
}
//////////////////////////////////////////////////////////////////////
void tip2() {
int x;
x == 2 + 2;
// This erroneous line has no effect
// After testing x against the value 4, the true/false
// answer is discarded.
x = 4; // This is correct
}
//////////////////////////////////////////////////////////////////////
void tip3() {
int x;
if (x = 4) {
x = 6;
}
}
//////////////////////////////////////////////////////////////////////
void tip4() {
double max = 0.0;
int count = 0;
double positive_numbers[4] = {1.0, 5.65, 42.0, 0.01};
while (count < 4) {
if (positive_numbers[count] > max) {
max = positive_numbers[count];
}
}
}
//////////////////////////////////////////////////////////////////////
void tip5() {
double p, q;
double tolerance = 1.0e-8;
int k;
if (std::fabs(p - q) < tolerance) {
k = 0;
}
}
//////////////////////////////////////////////////////////////////////
int main(int argc, char **argv) {
Statement();
if_syntax();
if_short_syntax();
if_example1();
if_else_example();
multiple_if_example();
nested_if_example();
switch_statement();
bool_condition();
and_condition();
negation_condition();
or_condition();
while_statement();
do_while();
for_loops();
scalar_product();
tip1();
tip2();
tip3();
tip4();
tip5();
}

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