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 only use single character variables for loop control or very short functions.

for(int i = 0; i< endPoint; i++) {...}

int max( int a, int b) {
    if (a > b)
       return a;
    return b;
}

• The amount of information depends on the scope of the variable, the more places it could be used, the more information I want to have the name to keep track of its purpose.
• When I write example code, I try to use variable names as I would in real code (although functions might get useless names like foo or bar).
• See Etymology of "Foo"