:-D If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile. This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke [My articles]

yup, i know...i meant allocating memory for s1.. my concern wasn't on part where p=s. i thought application crashed due to NULL pointer on s1...that's why we must allocate memory for s1... :-D

the developer shouldn't rely on the order of the parameters. your inline printf() (the second example) is really bad. On Visual C++, the parameters are unstacked from right to left, so when you do printf("%d %d\n",a++,++a) ++a is evaluated before a++. this may be different on other compilers. for how the value of a vary, you have to know how pre and post increment operators work. Preincrement (++a) increments the variable and returns its new value (the value after the incrementation). Postincrementation (a++) increments the variable ans returns its old value (the value before the incrementation). [VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

There is no rule when to use constants or when to use preprocessors.. It is always better to use constants because it is typed.