Help with while

[sumaraghavi ragha]

class NoBody
{
public static void main(String[] args)
{
int i,j;
i=100;
j=200;
while(++i ==102)
System.out.println("Mid point is" + i);
}
}
Why their is no output?

[damodar kumar]

because at first i value is 100, in expression ++i its preincrementing i to 101 and checking with 102 whether it is equal or not , it is not equal so it comes put of loop ans again the i value is 100 only , so it wont print any output

[Mark Vedder]

Originally posted by damodar kumar:
because at first i value is 100, in expression ++i its preincrementing i to 101 and checking with 102 whether it is equal or not , it is not equal so it comes put of loop ans again the i value is 100 only , so it wont print any output

Actually, when it comes out of the "loop", its value is still 101 since nothing else changes i's value or decrements it.

[Mark Vedder]

sumaraghavi,

You are probably looking to do something more along the lines of this:

int i = 100;
while(++i <= 101)
{
   if (i == 102)
   {
        System.out.println("Mid point is" + i);
   }
}

but that would be an unusually construct. Generally, when using a counter or index, like i, a 'for' loop is used rather than a 'while' loop. While both a 'while' loop and a 'for' loop would be syntactically correct, the 'for' loop is more conventional, and easier to understand. So it will make your code easier for others to read and understand.

for (int i = 100; i <=  102; i++)
{
    System.out.println(i);
    if (i == 102)
    {
        System.out.println("Mid point is" + i);
    }
}

if you need i to be in scope after the 'for' loop, you can do this:

int i = 100;
for (; i <=  102; i++)
{
    System.out.println(i);
    if (i == 102)
    {
        System.out.println("Mid point is" + i);
    }
}
System.out.println("i is still in scope and its value is: " + i);

[ June 02, 2008: Message edited by: Mark Vedder ]

[sumaraghavi ragha]

Thanks all