Follow this lesson in Ullman Chapter 4. The scripts are located in the 04 directory.
See the page calculator.html described on Ullman pages 68ff.
See the page handle_calc.php described on Ullman pages 71ff.
Particularly note these lines:
// In case register_globals is disabled.
$price = $_POST[‘price’];
Operator | Purpose | |
-$a
|
Negation | Opposite of $a. |
$a + $b
|
Addition | Sum of $a and $b. |
$a – $b
|
Subtraction | Difference of $a and $b. |
$a * $b
|
Multiplication | Product of $a and $b. |
$a / $b
|
Division | Quotient of $a and $b. |
$a % $b
|
Modulus | Remainder of $a divided by $b. |
Combined Operators
|
Same as: | |
$a += $b
|
Addition | $a = $a + $b |
$a -= $b
|
Subtraction | $a = $a – $b |
$a *= $b
|
Multiplication | $a = $a * $b |
$a /= $b
|
Division | $a = $a / $b |
$a %= $b
|
Modulus | $a = $a % $b |
Incrementing/Decrementing | ||
a++
|
Increment | $a = $a + 1 |
a–
|
Decrement | $a = $a – 1 |
See the page random.php.
Examine the different versions of handle_calc.php. What are the differences, and why are they significant?
Create your own page that demonstrates round() or number_format(). It should have text boxes that take a decimal number, and a number to round by.
Review Chapter 4 of Ullman.