02.2b: Bug Types

Software written by even the most seasoned software developer will still have bugs. In this lesson, we look at the two most common types of software bugs: Syntax bugs and logic bugs.

<?php
# * -------------------------------------------------
# * Types of bugs; syntax vs logic

# * -------------------------------------------------
# * Syntax bug

$j = 5
$n = $j + 5;

print "n: $n\n";



# * -------------------------------------------------
# * Logic bug
$a = 5;
$b = 3;

$sum = $a + $b;

print "sum of $a + $b = $sum\n";



# * Mars rover miles vs kilometers.
$m = 1;
$k = $m * 1.6;

print "There are $k kilometers in $m mile(s).\n";





# * -------------------------------------------------
# * How to debug?
# * Calculate total square footage of 2 rooms:

$height1 = 10;
$width1 = 10;

$height2 = 10;
$width2 = 20;

$room1_sq_ft = $height1 * $width1;
$room2_sq_ft = $height2 + $width2;

$total_sq_ft = $room1_sq_ft + $room2_sq_ft;
print "Total sq ft: $total_sq_ft\n";





?>