CPlusPlus20ForProgrammers-master/examples/ch06/fig06_02.cpp

@@ -1,6 +1,6 @@
 // fig06_02.cpp
 // Initializing an array in a declaration.
-//#include <format>
+#include <format>
 #include <iostream>
 #include <array>
 
@@ -9,7 +9,7 @@ int main() {
 
    // output each array element's value
    for (size_t i{0}; i < values.size(); ++i) {
-      std::cout <<  values.at(i) << "\n";
+      std::cout << std::format("{}  ", values.at(i));
    }
 
    std::cout << "\n\n";
@@ -19,7 +19,7 @@ int main() {
 
    // output each array element's value
    for (size_t i{0}; i < values2.size(); ++i) {
-      std::cout <<  values2[i] << "\n";
+      std::cout << std::format("{}  ", values2.at(i));
    }
 
    std::cout << "\n";

CPlusPlus20ForProgrammers-master/examples/ch06/fig06_03.cpp

@@ -8,14 +8,10 @@ int main() {
 
    std::array items2{1, 2, 3, 4, 5};
    // display items before modification
-
-   for (int i{0}; i<items.size();i++)
-       std::cout <<  items[i] << "<-- items\n";
    std::cout << "items before modification: ";
    for (const int& item : items) { // item is a reference to a const int
       std::cout <<  item << "<-- items\n"; 
    }                       
-
    std::cout << "items2 before modification:\n";
    for (const int& item : items) { // item is a reference to a const int
       std::cout <<  item << "<-- items2\n";
@@ -42,6 +38,8 @@ int main() {
    for (const int& item : items2) {
       std::cout <<  item << "<-- items2\n";
    }
+
+
    // sum elements of items using range-based for with initialization
    std::cout << "\n\ncalculating a running total of items' values:\n";
    for (int runningTotal{0}; const int& item : items) {

CPlusPlus20ForProgrammers-master/examples/ch06/fig06_04.cpp

@@ -8,15 +8,11 @@ int main() {
    constexpr size_t arraySize{5}; // must initialize in declaration
 
    std::array<int, arraySize> values{}; // array values has 5 elements
-/*
+
    for (size_t i{0}; i < values.size(); ++i) { // set the values
       values.at(i) = 2 + 2 * i;
    }
-*/
-   for ( int index{0}; int& value : values) {
-      value = 2 + 2 * index;
-      index++;
-   }
+
    // output contents of array values in tabular format
    for (const int& value : values) {
       std::cout << value << "\n";

CPlusPlus20ForProgrammers-master/examples/ch06/fig06_06.cpp

@@ -1,6 +1,6 @@
 // fig06_06.cpp
 // Printing a student grade distribution as a primitive bar chart.
-
+#include <format>
 #include <iostream>
 #include <array>
 

CPlusPlus20ForProgrammers-master/examples/ch06/fig06_07.cpp

@@ -11,25 +11,19 @@ int main() {
    std::default_random_engine engine{rd()}; // rd() produces a seed 
    std::uniform_int_distribution randomDie{0, 6};
 
-   std::uniform_real_distribution<double> randomReal{0, 1};
-
    constexpr size_t arraySize{7}; // ignore element zero
    std::array<int, arraySize> frequency{}; // initialize to 0s
 
-
-   constexpr size_t N{7};
-   std::array<double, N> histogram{};
-
    // roll die 60,000,000 times; use die value as frequency index
    for (int roll{1}; roll <= 60'000'000; ++roll) {
-       randomReal(engine);
+      ++frequency.at(randomDie(engine));
    }
 
    std::cout <<  "Face " <<  " Frequency  \n";
 
    // output each array element's value
-   for (size_t face{1}; face < histogram.size(); ++face) {
-      std::cout << face << " " << histogram.at(face) << "\n";
+   for (size_t face{1}; face < frequency.size(); ++face) {
+      std::cout << face << " " << frequency.at(face) << "\n";
    }
 }