Logical meaning  & - > and | - > OR ! - > Not   > for(year in 2000:2018){ +   if (year%%4==0 & year%%100!=0 | year%%400==0){ +     result <-

Most programming languages have an implementation for the for()-loop. In subcode it looks like: for ( counter; condition; counterchange) { // do something } An actual code snippet in PHP would look like

Writing up the codes within a new File Up until now, we have only been using IDLE's main window to write codes. This is totally fine for simple tasks but will be a nuisance once the codes are long and