PHP and MySQL
Introduction to
PHP and MySQL
Kirkwood Center for
Continuing Education
By Fred McClurg, frmcclurg@gmail.com
© Copyright 2010 All Rights Reserved.
1
Chapter Six
Hurray for Array Functions
http://webcert.kirkwood.edu/~fmcclurg
/courses/php/slides/chapter06.functions.
ppt
2
Array Function: “array_push”
Description: Adds one or more elements to the end of an array.
Syntax: array_push( &$array, $elements );
Example:
<?php
$obj = array( "rock" ); array_push( $obj, "paper",
"scissors" );
?> for ( $i = 0; $i < count($obj); $i++ ) printf( "\$obj[%d]: %s<br />",
$i, $obj[$i] );
3
Array Function: “array_pop”
Description: Removes the last element of an array and returns that value.
Syntax:
$last = array_pop( &$array );
Example:
<?php
$stooge = array( "Moe", "Larry",
"Curly" );
$best = array_pop( $stooge ); for ( $i = 0; $i < count($stooge); $i++ ) printf( "\$stooge[%d]: %s<br />",
$i, $stooge[$i] );
?> printf( "<p />" ); printf( "\$best: %s", $best );
4
Array Function: “array_unshift”
Description: Adds one or more elements to the beginning of an array.
Syntax: array_unshift( &$array, $elements );
Example:
<?php
$stooge = array( "Moe", "Larry" ); array_unshift( $stooge, "Shemp" );
?> for ( $i = 0; $i < count($stooge); $i++ ) printf( "\$stooge[%d]: %s<br />",
$i, $stooge[$i] );
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Array Function: “array_shift”
Description: Removes the first element of an array and returns that value.
Syntax:
$first = array_shift( &$array );
Example:
<?php
$narnia = array( "Peter", "Susan", "Lucy",
"Edmund" );
$highKing = array_shift( $narnia ); for ( $i = 0; $i < count($narnia); $i++ ) printf( "\$narnia[%d]: %s<br />",
$i, $narnia[$i] );
?> printf( "\$highKing: %s", $highKing );
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Array Function: “shuffle”
Description: Arranges array values in random order.
Syntax: shuffle( &$array );
Example:
<?php
$deck = array( "Ace", "King", "Queen", "Jack",
"Joker" ); shuffle( $deck ); // randomize array
?> for ( $i = 0; $i < count($deck); $i++ ) printf( "\$deck[%d]: %s<br />",
$i, $deck[$i] );
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Array Function: “sort”
Description: Sorts the array in alphabetical order.
Syntax: sort( &$array );
Example:
<?php
$torah = array( "Genesis", "Exodus",
"Leviticus", "Numbers",
"Deuteronomy" ); sort( $torah ); // sort array by value
?> for ( $i = 0; $i < count($torah); $i++ ) printf( "\$torah[%d]: %s<br />",
$i, $torah[$i] );
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Array Function: “array_reverse”
Description: Reverses the order of the array values.
Syntax:
$arrayNew = array_reverse( $arrayOld );
Example:
<?php
$name = "rumpelstiltskin";
// convert string to array
$pieces = str_split( $name );
// reverse the array order
$reverse = array_reverse( $pieces );
// convert array back to string
$backward = implode( "", $reverse );
?> echo $backward;
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Array Function: “array_splice”
Description: Removes a portion of an array and replace it with something else.
Syntax:
$aryRm = array_splice( &$input, $offset[, $length=0 [, $replacement]] );
Example:
<?php
$deck = array( "Ace", "King",
"Queen", "Jack",
"Joker" );
$max = count($deck) - 1;
$offset = rand( 0, $max );
// draw one random card
$drawn = array_splice( $deck, $offset, 1 ); printf( "Card drawn: %s<br />", $drawn[0] ); printf( "Remaining deck:<br />" );
?> for ( $i = 0; $i < count($deck); $i++ ) printf( "\$deck[%d]: %s<br />",
$i, $deck[$i] );
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Don’t get angry, just walk array!
array_walk(): Send value/key pairs of an associative array to be handled by a user defined function.
User Defined Function Syntax:
<?php
function functName( $value, $key )
{
...
}
?> array_walk( $hash, 'functName' );
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“array_walk” Example
<?php
function printRow( $value, $key )
{ printf( "
<tr>
<td> $key </td>
<td> $value </td>
</tr>\n" );
}
$color = array( 'Red' => '#FF0000',
'Green' => '#00FF00',
'Blue' => '#0000FF',
'Yellow' => '#FFFF00' );
?> array_walk( $color, 'printRow' );
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Student Exercise 6.3 Array Functions
Problem: Write a string scramble simulation game. The order of the characters shall be randomized.
Input: Initialize a variable to a word or string to be scrambled.
Output: Display the original string and the randomized string to the screen.
Hint One: Use the predefined functions, “str_split()”,
“shuffle()” and “implode()” to make the task easier.
Hint Two: See example for “array_reverse()”.
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Student Solution 6.3 Array Functions
<?php
$word = "randomize";
// break each char into array
$pieces = str_split( $word );
// randomize the array shuffle( $pieces );
// convert elements into string
$scramble = implode( "",
$pieces );
?> printf( "Original: %s<br />
Scrambled: %s<br />",
$word, $scramble );
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Student Exercise 6.4 Array Functions
Problem: Write a sentence scramble simulation game.
The order of the words shall be randomized. The words themselves shall not be scrambled.
Input: Initialize a variable to number of words or a sentence to be scrambled.
Output: Display the original sentence and the randomized sentence to the screen.
Hint One: Solution will be similar to Exercise 6.2
Hint Two: Use predefined function “explode” instead of
“str_split”.
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Student Solution 6.4 Array Functions
<?php
$sentence = "Now is the time for all good men to pray for the aid of their country.";
// at a space, break each word into an array
$words = explode( " ", $sentence );
// randomize the array shuffle( $words );
// join elements into string with spaces
$scramble = implode( " ", $words );
?> printf( "Original: %s<p />
Scrambled: %s", $sentence, $scramble );
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to be continued ...
http://webcert.kirkwood.edu/~fmcclurg/cour ses/php/slides/chapter08a.fundamentals.ppt
