Initialization of variables in c++

Initialization of variables

When declaring a regular local variable, its value is by default undetermined. But you may want a variable to store a concrete value at the same moment that it is declared. In order to do that, you can initialize the variable. There are two ways to do this in C++:

The first one, known as c-like, is done by appending an equal sign followed by the value to which the variable will be initialized:
type identifier = initial_value ;
For example, if we want to declare an int variable called a initialized with a value of 0 at the moment in which it is declared, we could write:

int a = 0;

The other way to initialize variables, known as constructor initialization, is done by enclosing the initial value between parentheses (()): 



type identifier (initial_value) ;
For example:

int a (0);

Both ways of initializing variables are valid and equivalent in C++.

// initialization of variables   #include <iostream> using namespace std;   int main () {   int a=5;               // initial value = 5   int b(2);              // initial value = 2   int result;            // initial value undetermined     a = a + 3;   result = a - b;   cout << result;     return 0; }

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