Learn to Code
John F. Dumas
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Why Learn C++?
► It is fast. You will see c++ used frequently in industries like gaming and high frequency trading where speed is critical.
► It has a wonderful feature (the destructor) that allows us to manage resources and guarantee they are released correctly and in a timely manner. This feature is used in a programming technique called RAII (resource acquisition is initialization) and is crucial for industries that require predictability and accuracy such as: finance, real-time and embedded high performance systems.
► C++ is powerful and expressive. You can do a great deal more in a few lines of C++ code that you could in the same amount of C code.
Here's an example showing how some of that power and expressiveness (file: test.cpp):
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>
#include <cctype>
#include <map>
int main()
{
std::ifstream in("finn.txt");
if(!in)
{
std::cout << "Could not open file\n";
return(1);
}
std::map<char, int> letterToCount;
for(char c : "abcdefghijklmnopqrstuvwxyz")
letterToCount[c] = 0;
std::string line;
int maxCount = 0;
while(getline(in, line))
for(char c : line)
if(isalpha(c))
maxCount = std::max(maxCount, ++letterToCount[(char)tolower(c)]);
for(int i = maxCount; i > 0; i --)
for(auto pair : letterToCount)
if(pair.second == i)
std::cout << std::setw(3) << i << ": " << pair.first << "\n";
return(0);
}
When executed, the above program outputs:
181: t 172: e 147: a 143: o 111: n 107: h 107: i 98: d 81: s 78: l 72: r 62: u 61: w 49: m 40: g 38: b 36: y 31: c 21: f 19: p 14: k 11: v 3: j 2: x 1: z
A list of all letters that occurred in the text file is shown, sorted by frequency (most common to least common).
► As of July, 2021, the TIOBE Index of programming popularity was:
As you can see, c++ is quite popular
► A great deal of the software that we use day-to-day is written in C++ such as:
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