Question

I just found … AGAIN … a real time wastage bug as follows

for (int i = 0; i < length; i++)
{ //...Lots of code 
    for (int j = 0; i < length; j++)
    {
        //...Lots of code 
    }
}

Did you notice straight ahead the inner i which SHOULD BE j ? Neither did I. So from now on I am going to use:

for (int i = 0; i < length; i++)
{
    for (int i1 = 0; i1 < length; i1++)
    {
    }
}

What are your tips for inner and outer while and for loops ?

Edit: Thanks for the valuable responses. Herewith short summary of the proposed tips:

• use meaningful variables names for index variables ( instead i use SomeObjCollectionLength )
• place the contents of the inner loop into a separate method and call that method from the outer loop
• not manageable amount of lines of code between the outer and inner loop is a strong signal for code smell
• avoid copy pasting and rushing , write the index vars with care

You might want to check the summary by LBushkin for the following

• use foreach and iterators whenever possible
• initialize the variables just before entering the loops
• Make each loop perform only one function. Avoid mixing responsibilities in a single loop
• When possible, make your loops short enough to view all at once

Answer 1

Don’t use i & j (or any other single letter variable) as index names. Use proper names and you will not get into this type of problems.