Increment operators (++)
- Increment operators are increase the value of subsequent. value may be increase according to the programmer.
- Increment operator are two types as follows :
- Post increment
- Pre increment
Decrement operators ( -- )
- decrement operators decrease the value to one, two and so on.
- As like Increment operators, decrement operators are also two type as :
- Post decrement
- Pre decrement
Before we more discuss about increment and decrement operator, let understand some expression; that's are using in all operators.
Now some issues of pre and post increment and decrement, we will discuss after solve following programming :
Now some issues of pre and post increment and decrement, we will discuss after solve following programming :
x = 5 x = 5 x = 5
x = x+1 ++x x++
x = 6 x = 6 x=5
In above program u notice that value of x increase to one in all three expression but after the increasing one, the final value of x in not same, third box result is differ to another two boxes. Now you know that c operators are mostly three types, ++ and -- operators are Unary operators.
Post increment or decrement are lowest precedence so it is solve at the end of program. Hence above program in third box first value of x is print i.e. 5 after, it is increase.
Unary operators are solve right to left.
Post increment or decrement are lowest precedence so it is solve at the end of program. Hence above program in third box first value of x is print i.e. 5 after, it is increase.
Unary operators are solve right to left.
Q.1 Solve the expression in C language compiler ,assuming x,z are integer variables:
z = x++ + x++
where x=7
stepwise evaluation of this expression is shown below :
z = x++ + x++ + ++x
//post increment of x=2
z = x + x + ++x
//++x increase the value of x one so x=8
/*Now all pre and post increment/decrement are solved so we write the the expression in normal mathematical expression*/
z = x + x + x
//put the current value of x i.e. 8
z = 8 + 8 + 8
z = 24
syntax : x=current value-post increment/decrement
so x = 8 + 2
x = 10
Q.2 Solve the following expression :
z = ++x + y-- - ++y - x-- - x-- - ++y - x--
where x = 7
y = -3
Ans.
z=++x + y-- - ++y - x-- - x-- - ++y - x--
/* post decrement of x=3 and
post decrement of y=1 */
z= ++x + y - ++y - x - x - ++y - x
/* its unary operator so we solve it from
right to left*/
z=++x + y - ++y - x - x - y - x
//now y=-3+1=-2
z=++x + y - y - x - x - y - x
//now y=-2+1=-1
z=x + y - y - x - x - y - x
//now x=7+1=8
/*now all increment and decrement operators
all solved so we put the current value of x
and y.*/
z= 8 + (-1) - (-1) -8 - 8 - (-1) - 8
z= 8 - 1 + 1 - 8 - 8 + 1 - 8
z= - 16 + 1
z= -15
x=8-3=5
y=-1-1=-2
Related some increment or decrement operators exercise:
Q.3 solve the following equations:
z = x++ + ++y - x-- + --y
where x = 7 and
y = 9
hint:(For your cross-checking, answer is x=7, y=9 and z=18).
Q.4 solve the following equations:
z = x++ * y++ / ++x - --y % x++
where x = 5 and
y = 2
hint:(For your cross-checking, answer is x=8, y=2 and z=0).
--------------------------------------------------------------------------------
Q.3 answer with explanation :
z = x++ + ++y - x-- + --y
where x = 7 and
y = 9
Ans:
post decrement of x = 1
post increment of x = 1
z = x + ++y - x + --y
z = x + ++y - x + y // now y = 9-1 = 8
z = x + y - x + y // now y = 8+1 = 9
// now put the value of x and y
z = 7 + 9 - 7 + 9
z = 9 + 9
z = 18
Hence, our final answer will be:
x = 7 - 1 + 1 = 7
y = 9
z = 18
Related program:
What will be output of below program:
int i=1;
printf("%d%d%d",i,++i,i++);
Click here for answer.
