PHP 101 (part 3) - Chocolate Fudge And Time Machines - Anyone For Apple Pie? (
Page 5 of 9 )
PHP
offers one more type of loop, the "foreach" loop, which is designed specifically
for use with array variables. Logic would suggest that we explain array variables
before we attempt to teach you the "foreach" loop...and you know what slaves we
are to logic!
Thus far, the variables you've used contain only a single value - for example,
$i = 0
However, array variables are a different kettle of fish altogether. An array
variable can best be thought of as a "container" variable, which can contain one
or more values. For example,
$desserts = array("chocolate mousse", "tiramisu", "apple pie", "chocolate
fudge
cake");
Here, $desserts is an array variable, which contains the values "chocolate mousse",
"tiramisu", "apple pie", and "chocolate fudge cake".
Array variables are particularly useful for grouping related values together
- names, dates, phone numbers of ex-girlfriends et al.
The various elements of the array are accessed via an index number, with the
first element starting at zero. So, to access the element
"chocolate mousse"
you would use the notation
$desserts[0]
while
"chocolate fudge cake"
would be
$desserts[3]
- essentially, the array variable name followed by the index number enclosed
within square braces. Geeks refer to this as "zero-based indexing".
Defining an array variable is simple via the array() function - here's how:
$past_flames = array("Jennifer", "Susan", "Tina", "Bozo The Clown");
The rules for choosing an array variable name are the same as those for any other
PHP variable - it must begin with a letter, and can optionally be followed by
more letters and numbers.
Alternatively, you can define an array by specifying values for each element
in the index notation, like this:
$past_flames[0] = "Jennifer";
$past_flames[1] = "Susan";
$past_flames[2] = "Tina";
$past_flames[3]
= "Jennifer";