PLS HELP ME

Question

b= 3
b=b++
COUT <<b<<ENDL;

what is the output and pls help me what is the concept of putting 2 plus signs after b

Answer 1

b++ : b+= 1

Answer 2

First please note that C++ is case sensitive so you will need to write 'cout' and 'endl'.

b++ is an expression. By writing ++ after b you are using the post-increment operator. 'Post' here means 'after'. Post-increment has the side effect of incrementing (adding a unit to) the value of b after getting the current value of b. So b++ gives the current value of b (3) and then increments b, which changes it to 4. Then you assign (=) what was the current value of b (3) to b, overwriting the new value in b (4) with its previous value (3). Then the value of b (3) is output.

If you intended to add 1 to b you can use one of several idioms:

b = b + 1;
b += 1;
b++;
++b;

Which to use depends on context and style. The third form (b++) is the most popular. That is a hold over from the C programming language. Strictly speaking, this requires a call to the copy constructor for b. I prefer the last form (++b), because it avoids using the copy constructor (improving speed and reducing memory use).

Finally, to understand what is happening in your expression (b = b++) you need to understand that the processor does one thing at a time using operator precedence. ++ has higher precedence than =. So, ++ is done first, followed by =.

Also, there are two elements to ++. Getting a value from a variable; incrementing that variable. With pre-increment (++b) the variable is incremented and its new value is retrieved. Post-increment (b++) retrieves the current value of the variable, saving a copy for the next step in the expression evaluation (by calling the copy constructor). Then it modifies the value of the variable.

Sorry for the long answer to a straight-forward question, but getting a solid grasp of theses concepts is required to be an effective programmer.

Answer 3

b++ : b=b+1
output : 4

Answer 4

Hi!
firstly here some error in your code to write correct code like that:
int b = 3;
b = b++
cout << b << endl;

because C++ is a case sensitive language so Compiler don't under stand the meaning of COUT & ENDL

Now C++ is a strong language so every variable has a data type as int.
b = b++
The increment operator ( ++ ) which is also know as postfix operator.
Firstly b = b++ is an increment operator which perform increment operator as b = b +1;
Secondly you just print the b value so the answer is just 3.

if you you want to print the incremented value you must add an extra line above the cout << b <<endl; as

cout << b++ << endl;
cout << b << endl;

Now the output is
3 // b++ has 3
4 // now b has 4 value because b++ get the value and then increment the value.
For Example :
We use as postpaid mobile network , firstly we use the data and after the end of the month we pay bill same as firstly we b = b++ get the value and then allot the value. so the after the execution finaly b = b++ has 3 value only.

if we change a little in the code
b = 3;
a = b++;
cout << b++ << endl;
cout << b << endl;

Answer 5

The output is 4.
Shen you write a variable and ++ you add 1 to it's, and -- you remove 1.