How to name variables

Question

• What rules do you use to name your variables?
• Where are single letter vars allowed?
• How much info do you put in the name?
• How about for exam

Answer 1

I never use meaningless variable names like foo or bar, unless, of course, the code is truly throw-away.

For loop variables, I double up the letter so that it's easier to search for the variable within the file. For example,

for (int ii=0; ii < array.length; ii++)
{
    int element = array[ii];
    printf("%d", element);
}