C++Primer Fifth Edition: Exercise 2.9 2.10

Exercise 2.9

#include<iostream>

int main()
{
    
    
	int input_value;
	std::cin >> input_value;

	int i = {
    
     3 };

	double salary, wage;
	salary = wage = 9999.99;

	int j = 3.14;
}

a: Illegal variables defined in the input
b: List initialization will re-initialize the value when there is a risk of losing information
c:wage is the assignment is not defined
d: correct, but the data will be lost

Exercise 2.10

#include<iostream>

std::string global_str;
int global_int;

int main()
{
    
    
    int local_int;
    std::string local_str;
}

global_str: empty string
global_int: 0
local_int: uninitialized, undefined value (built-in type in the function)
local_str: empty string