C Programming - Control Instructions - Discussion

Look when inside the loop the expression (y = x++ <= 5) gets evaluated, then it is the value of x not the incremented value gets compared. Post increment operator increases the value after the variable's use.

SO the things will proceed like this:

1] y = x++ <= 5.
x=1 will get compared and after comparison.
y=1, x=2.
then print statement is executed for x=2 and y=1 (explained above).

2] x=2 will get compared and after comparison.
y=1, x=3.
then print statement is executed for x=3 and y=1 (explained above).

3] x=3 will get compared and after comparison.
y=1, x=4.
then print statement is executed for x=4 and y=1 (explained above).

4] x=4 will get compared and after comparison.
y=1, x=5.
then print statement is executed for x=5 and y=1 (explained above).

5] x=5 will get compared and after comparison.
y=1, x=6.
then print statement is executed for x=6 and y=1 (explained above).

6] x=6 will get compared and after comparison.
y=0, x=7.
then print statement is executed for x=7 and y=0.

Now after 6th step y=0, therefore the loop execution condition failed and loop will be exited.

If 6<=5 the condition will become false then how it will print last one i.e. 7 0.

I will explain this in easy manner.

We have [y=(x++<=5)] if u observe carefully it consists of
2 valuable expression with in this.

Simple funda is: T T T(1)
F F F(0)

If x<=5 is (true) then expression (x++<=5) is always (true) , that means it have the value 1 , and y will be true
always(1).

If x>=5 is (false) then expression (x++>=5) is always (false) ,that means it have the value 0 , and y will be false always(0).

That is why last step will be [7 0].

The above program can be write like this in while loop:

while(y)
{
y=x++<=5;
pf("%d %d"x,y);
}

But why the "y" value did not change? In y=x++<=5; after the first incrementation y=2++<=5. Why shouldn't the incremented value of x=2 is assigned in "y"? can anyone explain?

Because here y takes the value true or false if true than it get prints 1 otherwise 0 you can change the value of y in the program and check that value of y doesn't matter it will only work on true or false of x++<=5 condition it will print 1 until this condition becomes true and value of x is incremented in every step after the use of x and the incremented value is stored at the position of previous value of x and that's why it take the value from that address and prints the value but it doesn't take value of y from that position because it only takes the answer of true false condition.

Thanks everyone for giving the time to explain this.

Thanks @Kiran.

Thank you all my friends.

Before one increment of x, there is one printf statement due to which once x should be printed 1.

Thanks @Kiran.