why does it always printone number

Question

int num=1;
while(num>6)｛
cout<<num<<endl;
num=num++；
｝
why it doesnt print 12345？

Answer 1

also your condition is false. change it to num<6

Answer 2

It actually doesn't print anything, right?
The first line says that num is 1, and the second asks if 1 is bigger then 6 which is false. Though it never enters in your while loop.

The correct would be:
int num=1;
while (num < 6)｛
cout << num << endl;
num++；
｝

Answer 3

if you want increase your counter, in this case num, you can use one of this statements:
num++;
++num;
num = num + 1;
num = ++num;

apparently your way of increasing num is known as "undefined behaviour" and it is a complicated issue to understand by new programmers such me.
so dont use this:
num = num++;