Loop optimizations

for(i;i<list.length;i++){
}

Looks familiar?
Well loops help us in writing less code, we use the everyday but do we use them effectively.
Here are some tips:
1. Avoid queries in loops.
If you put a query in a loop it means the loop has to do a trip to db each time.
2. If you are going to use conditions break them down and try to organize them logicaly.e.g.
for(i;i<list.length;i++){
      if(condition)
             if(condition)
                   
                   for(k;k<list.length;k++){
           
The logic is the first condition is never met the second loop will never run, but the second condition has to be met too.