This question already has answers here:
C macros and use of arguments in parentheses
(2 answers)
C Programming Macros multiplication [duplicate]
(2 answers)
Closed 2 years ago.
#include <iostream>
using namespace std;
#define MULTIPLY(a, b) a*b
int main(){
cout << MULTIPLY(2+3, 3+5);
return 0;
}
I expected this to print 40 since five times eight is forty. Why does it print 16?
Because C++ macros are not functions. They are text copies, so that means:
cout << 2+3*3+5;
Which is 2 + (3*3) + 5
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Since I am new to C++, I do not know what the expression means?
and how can i co-relate this expression with C language.
#include <bits/stdc++.h>
using namespace std;
int main()
{
// string to be converted to lowercase
string s = "GEEKSFORGEEKS";
for (auto& x : s) {
x = tolower(x);
}
cout << s;
return 0;
}
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Why are these constructs using pre and post-increment undefined behavior?
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Undefined behavior and sequence points
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Closed 19 days ago.
I was just messing with a piece of cpp code that I came across something I couldn't find an explanation for.
when I run this in c++:
int a = 5;
cout << (--a) * (--a);
9 is printed in the console. but when you get the variable (a) from the input, and then give it the same value (5), the result is different:
int a;
cin >> a;
cout << (--a) * (--a);
when you enter 5 as the input, 12 is printed in the console. Why is it so?
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What are the differences between C-like, constructor, and uniform initialization?
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Initialization difference with or without curly braces in C++
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What are the advantages of list initialization (using curly braces)?
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Closed 4 years ago.
In c++ what is the difference between initializing an object with round or angled braces like in this example?
#include <iostream>
#include <string>
int main()
{
std::string x = "abc";
std::string c(x);
//std::string c{x};
std::cout << "String c " << c;
return 0;
}
This question already has answers here:
integer indexed with a string in c++ [duplicate]
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With arrays, why is it the case that a[5] == 5[a]?
(20 answers)
Closed 4 years ago.
Consider the below syntax :
#include <iostream>
int main() {
std::cout << 1["ABC"] << std::endl;
}
The program outputs B which leads me to believe that it behaves as "ABC"[1]. Is that possible, what is the reason behind this ?
This question already has answers here:
Regular cast vs. static_cast vs. dynamic_cast [duplicate]
(8 answers)
What is the difference between static_cast<> and C style casting?
(7 answers)
Closed 9 years ago.
Code sample one:
float i=1.1f;
int j=static_cast<int>(i);
cout << j<< endl;
Code sample Two:
float i=1.1f;
int j=(int)i;
cout << j<< endl;
what's the difference between these code samples about converting in c++?