Expanding to Multidimensional Arrays in Java

Printer PDF-417 2d barcode in Java Expanding to Multidimensional Arrays

3 3 1 2 3 4 1 2 3 5 1 2 3 6 1 2 3 7 1 2 3 8 1

deck 0 deck deck deck 0 deck deck deck 0 deck deck deck 0 deck deck deck 0 deck deck deck 0 deck deck deck deck deck deck deck

2 3 9 1 2 3 10 1 2 3 11 1 2 3 12 1 2 3

deck deck 0 deck deck deck 0 deck deck deck 0 deck deck deck 0 deck deck deck deck deck deck deck

The entire table is the multidimensional array The far-left column in each set represents the indices of the parent array, which in this example is the card ranks Each index in the parent array contains its own sub-array, which in this example is the card suits Each index in the sub-array contains a value, which in this example is the location of the card All the cards are located in the deck in this example (you deal five to the player in the next section)

Using the table in the previous example as a guide representing the $cardLocation array, which holds your deck of cards, if you wanted to access the queen of diamonds, you d do so like this:

$cardLocation[11][1];

The first number in this example represents the card you want to access, the queen, which is stored in the indice 11 The next number in this example represents the rank you want to access, the diamonds, which are stored in the indice 1 So, the first number represents the indice in the parent array, and the second number is the indice for the child array in that spot in the parent array A longer, less convenient representation of this would be:

$queenSuits = $cardLocation[11]; $ownerOfCard = $queenSuits[1];

The value of $ownerOfCard in the latter example and $cardLocation[11][1] in the former example, is deck Now, try dealing five cards to the player (see Figure 5-2 for the output):

<h1>Card Hand</h1> <p> < //set up arrays $cardLocation = array(); $suits = array( heart , diamond , spade , club ); //fill deck for($rank=0; $rank<13; $rank++){ for($suit=0; $suit<4; $suit++){ $cardLocation[$rank][$suit] = deck ; } } print </p><p> ; //deal hand for($i=0; $i<5; $i++){ $duplicate = true; while($duplicate){ $suit = rand(1,4); $rank = rand(1,13); if($cardLocation[$rank][$suit] == deck ){ $cardLocation[$rank][$suit] = player ; $duplicate = false; print <img style= width: 150px; src= $suits[$suit] ($rank + 1) png /> ; } }

Here, you generate two random numbers to pick a card rank and suit Then, you check to see if that card is in the player s hand or in the deck If the card s in the deck, give it to the player by setting the value at that index to player instead of deck You do this until five different indices are set to player It s a bit beyond the scope of this chapter, but you can use all this to make a PHP poker game See the CD-ROM for the source code and the start of an algorithm for scoring poker hands

foreach loops are great for when you want to step through all elements of an array one by one and do something with them They work like a for loop, except they re much simpler:

1 Start with the foreach() function 2 Plug in the array ($languages, in this case) you want to use, followed

3 The keyword as, followed by 4 The variable you want to store the value of the current array indices

more than one line long) Take a look (see Figure 5-3 for the output):

<h1>Ancestry of PHP</h1> <ul> < $languages = array( FORTRAN , ALGOL58 , ALGOL60 , CPL , BCPL , B , C , sh , awk , PERL , PHP ); foreach($languages as $language){ print <li>$language</li> ; } > </ul> <p><a href= http://wwworeillycom/news/graphics/prog_lang_posterpdf >Reference: History of Programming Languages Timeline from O Reilly s website</a></p>