The University of Iowa
The College of Liberal Arts and Sciences
Department of Computer Science
Lecture/Lab #3
Declaration vs definition, function declaration, variables and types
import os
print( "Current directory:",
os.getcwd() )#include <iostream>
#include <filesystem>
int main() {
std::cout
<< "Current directory: "
<< std::filesystem::current_path()
<< "\n";
}Can we do this in C++?
int main() {
print( "Current directory:", getcwd() );
}Provide definitions of functions `print` and `getcwd` to make the program compile and produce the expected output
Open the exercise template
Write your code, press Run to test
When you're done, grab your Repl's link and send it as a direct message to me (agurtovoy)
Click on the corresponding option in the "Lab3 exercises" poll in #general
void hello( std::string name );
int main() {
hello( "Bob" );
}
A declaration makes a name known to the compiler and associates it with a type.
A definition creates/provides an implementation of the associated entity.
C++ allows multiple declarations of the same entity as long as declarations are identical.
Only one entity definition is allowed.
A declaration allows us to use the entity, but we need to provide the definition eventually to be able to compile the program into an executable.
void hello( std::string );
void hello( std::string name );
void hello( std::string fist_name );
void hello( std::string ignored ) {}
int main() {
hello( "Bob" );
}
Function parameter names are optional
Function parameter names can vary between declarations
Function parameter names can vary between a declaration and the definition
Fix the program's compilation errors without changing the order of function definitions
Open the exercise template
Write your code, press Run to test
When you're done, grab your Repl's link and send it as a direct message to me (agurtovoy)
Click on the corresponding option in the "Lab3 exercises" poll in #general
#include <iostream>
int main()
{
int n = 42;
float pi = 3.14;
bool b = pi < 5;
char c = 'A';
std::cout
<< "n: " << n << "\n"
<< "pi: " << pi << "\n"
<< "b: " << b << "\n"
<< "c: " << c << "\n"
;
}