C++ Crash Course: a fast-Paced Introduction

IOSTRE AMS, PRINTF, AND INPUT OUTPUT PEDAGOGY
People have really strong opinions about which standard output method to 
teach C++ newcomers. One option is 
printf
, which has a lineage that traces 
back to C. Another option is 
cout
, which is part of the C++ standard library’s 
iostream
library. This book teaches both: 
printf
in Part I and 
cout
in Part II. 
Here’s why.
This book builds your C++ knowledge brick by brick. Each chapter is 
designed sequentially so you don’t need a leap of faith to understand code 
examples. More or less, you’ll know exactly what every line does. Because 
printf
is fairly primitive, you’ll have enough knowledge by Chapter 3 to 
know exactly how it works. 
In contrast, 
cout
involves a whole lot of C++ concepts, and you won’t 
have sufficient background to understand how it works until the end of Part I. 
(What’s a stream buffer? What’s 
operator<<
? What’s a method? How does 
flush()
work? Wait, 
cout
flushes automatically in the destructor? What’s a 
destructor? What’s 
setf
? Actually, what’s a format flag? A 
BitmaskType
? Oh 
my, what’s a manipulator? And so on.)
Of course, 
printf
has issues, and once you’ve learned 
cout
, you should 
prefer it. With 
printf
you can easily introduce mismatches between format 
specifiers and arguments, and this can cause strange behavior, program 
crashes, and even security vulnerabilities. Using 
cout
means you don’t need 
format strings, so you don’t need to remember format specifiers. You’ll never 
get mismatches between format strings and arguments. Iostreams are also 
extensible
, meaning you can integrate input and output functionality into your 
own types. 
This book teaches modern C++ directly, but on this particular topic it 
compromises a bit of modernist dogma in exchange for a deliberate, linear 
approach. As an ancillary benefit, you’ll be prepared to encounter 
printf
specifiers, which is likely to happen at some point in your programming career. 
Most languages, such as C, Python, Java, and Ruby, have facilities for 
printf
specifiers, and there are analogs in C#, JavaScript, and other languages.

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