Web Programming for Information Retrieval

1. ArrayArray
Chapter 4
MOHAMAD RAHIMI MOHAMAD
ROSMAN

2. IntroductionIntroduction
An array can store one or more values in
a single variable name.
When working with PHP, sooner or later,
you might want to create many similar
variables.
Instead of having many similar variables,
you can store the data as elements in an
array.
Each element in the array has its own ID
so that it can be easily accessed.
MOHAMAD RAHIMI MOHAMAD
ROSMAN

3. Types of ArrayTypes of Array
There are three different kind of arrays:
◦ Numeric array
 An array with a numeric ID key
◦ Associative array
 An array where each ID key is associated with a
value
◦ Multidimensional array
 An array containing one or more arrays
MOHAMAD RAHIMI MOHAMAD
ROSMAN

4. Numeric ArraysNumeric Arrays
A numeric array stores each element with
a numeric ID key.
There are different ways to create a
numeric array.
◦ Example
 In this example the ID key is automatically
assigned:
$names = array(“Kamal",“Ahmad",“Ali");
MOHAMAD RAHIMI MOHAMAD
ROSMAN

5. ◦ Example 2
 In this example we assign the ID key manually:
$names[0] = “Kamal";
$names[1] = “Ahmad";
$names[2] = “Ali";
MOHAMAD RAHIMI MOHAMAD
ROSMAN
Variable name value

6. ExampleExample
 The ID keys can be used in a script:
MOHAMAD RAHIMI MOHAMAD
ROSMAN
<?php
$names[0] = "Peter";
$names[1] = "Quagmire";
$names[2] = "Joe";
echo $names[1] . " and " . $names[2] .
" are ". $names[0] . "'s neighbors";
?>
What is the output of the above script?

7. Associative ArrayAssociative Array
An associative array, each ID key is
associated with a value.
When storing data about specific named
values, a numerical array is not always
the best way to do it.
With associative arrays we can use the
values as keys and assign values to them.
MOHAMAD RAHIMI MOHAMAD
ROSMAN

8.  1st
technique
◦ $ages = array("Peter"=>32, "Quagmire"=>30, "Joe"=>34);
 2nd
technique
◦ $ages[‘Kamal'] = "32";
◦ $ages[‘Ahmad'] = "30";
◦ $ages[‘Ali'] = "34";
<?php
$ages[‘Kamal'] = "32";
$ages[‘Ahmad'] = "30";
$ages[‘Ali'] = "34";
echo “Kamal is " . $ages[‘Kamal'] . " years old.";
?>
MOHAMAD RAHIMI MOHAMAD
ROSMAN
What is the output of the above script?

9. Multidimensional ArraysMultidimensional Arrays
Multidimensional Arrays
◦ In a multidimensional array, each element in
the main array can also be an array
◦ Each element in the sub-array can be an array,
and so on.
MOHAMAD RAHIMI MOHAMAD
ROSMAN

10. ExampleExample
MOHAMAD RAHIMI MOHAMAD
ROSMAN
$families = array
(
"Griffin"=>array
(
"Peter",
"Lois",
"Megan"
),
"Quagmire"=>array
(
"Glenn"
),
"Brown"=>array
( "Cleveland",
"Loretta",
"Junior"
)
);
Array
(
[Griffin] => Array
(
[0] => Peter
[1] => Lois
[2] => Megan
)
[Quagmire] => Array
(
[0] => Glenn
)
[Brown] => Array
(
[0] => Cleveland
[1] => Loretta
[2] => Junior
)
) ;

11. ExerciseExercise
ID Name Class CGPA
2001 Rahul 3A 3.56
2002 Yunos 3B 3.49
2003 Mubin 3C 3.85
2004 Anuar 3D 3.63
MOHAMAD RAHIMI MOHAMAD
ROSMAN
Create four (4) array, namely:
•Id
•name
•class
•Cgpa
Then, assign those array into
the following statements:
Last week, a student named …………… , with
UiTM ID …………….., from class …………….
with a CGPA of ………….. has been choosen to
represent our university for a debate tournament

12. MOHAMAD RAHIMI MOHAMAD
ROSMAN