# Tutorial 3 ---  --- ### Questions from last week - Is there a way to do dice range and the Easter exercise without making everything a double? --- ### Overview - Code review - While Loops - Variable Names - #define - Operations and Datatype Conversions --- ### Code Review What to look for in a code review: - Purpose - Implementation - Legibility and Style Check this [Palantir guide for code reviews](https://medium.com/palantir/code-review-best-practices-19e02780015f) --- ### Code Review In industry, they also check for: - Maintainability - Security --- ### Code Review: Who's next? 2 pairs each week for the next 6 weeks - Josh and James - Carla and Kailin --- ### Variable Names * THX1138 * 2for1 * mr_bean * my space * event_counter * \^oo\^ * _MEMLIMIT * return --- ### Variable Names * THX1138 (Valid, not good - doesn't start with a lower-case letter) * 2for1 (Invalid - doesn't start with a letter or underscore) * mr_bean (Valid, good if the variable has something to do with Mr Bean) * my space (Invalid - you can't have spaces in variables names) * event_counter (Valid in C, good) * \^oo\^ (Invalid - only letters, numbers and underscore allowed) * _MEMLIMIT (Valid not good - doesn't start with a lower-case letter) * return (Invalid - this is a special keyword in C) --- ### Using #defines ```C= #include <stdio.h> #define FIRST_NUMBER 10 #define SECOND_NUMBER 20 #define TOTAL FIRST_NUMBER + SECOND_NUMBER #define AVERAGE TOTAL / 2 int main(void) { printf("The average of %d and %d is %d\n", FIRST_NUMBER, SECOND_NUMBER, AVERAGE); return 0; } ``` --- ### Operations and Datatype Conversions * 1 / 2 * 500 * 1 / 2.0 * 500 * (17 / 5) * 5 + (17 % 5) * (12 - 17) % 6 - 4 --- ### Operations and Datatype Conversions * 1 / 2 * 500 = 0 * 1 / 2.0 * 500 = 250.0 * (17 / 5) * 5 + (17 % 5) = 17 * (12 - 17) % 6 - 4 = -9 --- ### Implicit C Datatype Conversions  --- ### Conditionals [According to Wikipedia...](https://en.wikipedia.org/wiki/Leap_year#Algorithm) > if (year is not divisible by 4) then (it is a common year) else if (year is not divisible by 100) then (it is a leap year) else if (year is not divisible by 400) then (it is a common year) else (it is a leap year) --- ### Typed languages What does this mean? Why is this useful? --- ### Typed languages What does this mean? Why is this useful? - Easier debugging - Better control over memory --- ### Style is important! This week, please pick one piece of code from last week's lab to quickly be reviewed in lab for style. **Note:** This will not count towards marks, purely to help make sure you're getting into good habits!