Question

What values will be stored in x and y respectively after executing the following?

int = −10, y;

y= − − x;​

Answer 1

Correct Códe:-

int x= −10, y;

y= − − x;

Explanation:

• Initially x=-10
• y= --x means first x will decrease then it will be assigned to y
• y= -- -10
• y=-11

Answer:-

• x= -10
• y= -11

Answer 2

Answer:

int x= -10,y;

y= - -x

Answer:-

Final value of x= -11

Final value of y= -11

Reason:-

• Initially x is -10, y= - -x so,execution starts from right to left.
• -- x is pre increment so the value of y is decremented from -10 to -11 so the final value of y is -11.
• In the same way due to decrement of decrement of x the value of x also changes as the final value of x now becomes -11.
• Note if there is unary operators present in the variable say c like c=++x or c=x++ the value of the variable with which the increment/decrement is used changes.

Example:

int a=10,b;

b=a++;

If u are asked with the final value of b the answer will be

b=10 ,here it is why because it is post increment so the value changes after the action but if you are asked the final value of a then the answer is:

a=11

As the value assigned to b is 10 but the final value of a becomes 11.

So,a=11,b=10;

Case 2:-

Now, if a=10,b;

b= ++a;

If now you are asked the final value of b the answer will be 11 as now it's pre-increment so the value of b will be 11.

Now,if you are asked to find the final value of a then a will be also 11 as we know in unary operators the value of unary operators always changes so as the final value of a=11

So,a=11

Output:-

a=11 and b=11

More information:-

• In post-increment the value is first assigned then incremented.
• In pre-increment the value is first incremented and then assigned.

Hope you understood the concept