Writing a good code is a art. if a programmer follows some good programming habits then he can be a good programmer. Actually any code you write is likely to spend most its time in maintenance; application maintenance is a large expense. Establishing good coding habits will enhance design factors like modularity, and your code will be easier to understand and, thus, easier and cheaper to maintain. bad coding habits create defects in code and can cause code to be difficult to modify without introducing new defects.