# PHP I : Numbers

Creating a Calculator Form

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’];

Formatting Numbers

round()

number_format()

printf()

Operators

 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

Random Numbers

See the page random.php.

rand()

getrandmax()

mt_rand()

ceil()

floor()

abs()

To do for this section:

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.

To do out of class:

Review Chapter 4 of Ullman.