Challenging Output-based Problems on Operators and If Statements

#include<iostream>
using namespace std;

int main(){
    float i = 5.25;
    double j = 5.25;
    if(i == j)
        cout<<"Study"; 
    else 
        cout<<"Trigger"; 
    return 0; 
}

When the comparison i==j is performed, the C++ language performs implicit type conversion to promote float to double. This is because in C++, the promotion of data types follows a hierarchy, with float being lower than double.

As a result, the comparison i==j becomes 5.25==5.25, with both operands now being of type double. Since the values are equal, the condition in the if statement evaluates to true.

#include<iostream> 
using namespace std; 

int main() { 
   cout<<sizeof(2.5); 
   cout<<sizeof(2); 
   cout<<sizeof('A'); 
   return 0; 
}

#include<iostream> 
using namespace std; 

int main(){ 
   int n = -  -2; 
   cout<<n; 
   return 0; 
}

Let’s break down the expression step by step:

1. The first negative sign (‘-‘) is the unary negation operator. It negates the value that follows it.
2. The second negative sign (‘-‘) is also the unary negation operator. However, in this case, it is not negating a value but is used as a minus sign for subtraction.

When the code is executed, the expression ‘-  -2’ is evaluated as follows:

1. The first negative sign (‘-‘) negates the value ‘-2’, resulting in ‘2’.
2. The second negative sign (‘-‘) is interpreted as a subtraction operator.

As a result, the expression ‘-  -2’ is effectively evaluated as ‘2’, and the value ‘2’ is assigned to the variable ‘n’. When the code reaches the “cout << n;” statement, it will output the value of “n”, which is “2”. Therefore, the output of the code will be “2.”

#include<iostream>
using namespace std;

int main(){
    int n = --2;
    cout<< n;
    return 0;
}

#include<iostream>
using namespace std;

int main() {
    float a = 5.0;
    cout << "Result is " << (24 / 5) * a;
    return 0;
}

#include<iostream>
using namespace std;

int main(){
     int x=0;
     if(x == x)
         cout<<"Study";
     else
         cout<<"Trigger";
     return 0;
}

#include<iostream>
using namespace std;

int main(){
     int x=0;
     if(x)
        cout<<"Study";
     else
        cout<<"Trigger";
     return 0;
}

#include<iostream>
using namespace std;

int main(){
     if(true)
        cout<<"Study";
     else 
        cout<<"Trigger";
     return 0;
}

But if the above question asked in C-Language then the answer will be “Trigger” as there is no boolean literal “true”.

#include<iostream.h>
using namespace std;

int main(){
     int i = 5, j = 5;
     if(i == j);
        cout<<"Study";
     else
        cout<<"Trigger";
     return 0;
}

#include<iostream>
using namespace std;

int main() {
    int i = 2;
    if (i == (1, 2))
        cout << "Study";
    else
        cout << "Trigger";
    return 0;
}

Answer : option a) Study, In this code, the variable i is declared and initialized with the value 2.The if statement checks the condition i==(1,2). In this condition, the comma operator (,) is used between the values 1 and 2. The comma operator evaluates both expressions but returns the value of the rightmost expression, which is 2 in this case. Therefore, the condition i==(1,2) is equivalent to i==2.

Since i has the value 2, which is equal to 2, the condition i==2 evaluates to true.

When the condition in the if statement is true, the code inside the corresponding if block is executed. In this case, the statement cout<<“Study” is executed.