|
|
Line 28: |
Line 28: |
| By the end of class you should say: | | By the end of class you should say: |
|
| |
|
| | | * I understand sessions |
| * I understand the problem set, due before October break. [[Select a random student]] | | * I understand the problem set, due before October break. [[Select a random student]] |
|
| |
|
| |
| <syntaxhighlight lang="php">
| |
| <?php
| |
|
| |
| /* This file helps 9th and 10th grade (15 and 16 years old) students understand pragmatic and practical aspects of arrays as used in the PHP programming language.
| |
| */
| |
|
| |
| // this is where we define an array:
| |
|
| |
| $classes=["fighter","cleric","magic user","barbarian","monk"];
| |
| echo "<hr>";
| |
|
| |
| /* this is how we "dump" an array to see it (blech, ugly). When we dump an array we see the index, the type and the element. Take a look at the sample of part of var_dump below:
| |
|
| |
| ... [0]=> string(7) "fighter" [1]=> string(6) "cleric"...
| |
|
| |
| We can see at index zero we have a string which is 7 characters, "fighter". At index one we have a string which is 6 characters, "cleric"
| |
|
| |
| */
| |
|
| |
| var_dump($classes);
| |
| echo "<hr>";
| |
|
| |
| // this is how we access one element in an array. In this case we are selecting the element at index 2
| |
|
| |
| echo $classes[2];
| |
| echo "<hr>";
| |
|
| |
| // this is how we count elements in an array.
| |
|
| |
| echo count($classes);
| |
|
| |
| echo "<hr>";
| |
|
| |
| // this is how we ADD something to an array
| |
|
| |
| $classes[] = "Archer";
| |
| var_dump($classes);
| |
| echo "<hr>";
| |
|
| |
| // this is how we delete an item from an array.
| |
|
| |
| unset($classes[1]);
| |
| var_dump($classes);
| |
| echo "<hr>";
| |
|
| |
| // We often loop through an array. This is also called iterating through an array.
| |
|
| |
| foreach ($classes as $i) {
| |
|
| |
| echo "$i is an item in our array<br>";
| |
| # Looping through an array is a very powerful technique, especially when we combine PHP and HTML.
| |
| # echo "Please type a name for a $i : <input type=\"text\">";
| |
| }
| |
| echo "<hr>";
| |
|
| |
| // let's see if there is a specific element in our array:
| |
|
| |
| $searchTerm = "monk";
| |
| if(in_array($searchTerm,$classes)){
| |
|
| |
| echo "there is a monk in the array";
| |
|
| |
| } else {
| |
|
| |
| echo "there is not a monk in the array";
| |
| }
| |
| echo "<hr>";
| |
|
| |
| // let's find the index of something we want to search for:
| |
|
| |
| $indexOfSearchTerm = array_search($searchTerm,$classes);
| |
| echo "You are searching for $searchTerm. It looks like this element has been found at index $indexOfSearchTerm.";
| |
| echo "<hr>";
| |
|
| |
| // let's randomly select only one INDEX from our array
| |
|
| |
| $randomlySelectedClass = array_rand($classes,1);
| |
| echo "We have randomly selected an index from our array. This will most likely change every time you refresh the page. It is possible the same index will be
| |
| chosen again. The random index chosen is: $randomlySelectedClass";
| |
| echo "<hr>";
| |
|
| |
| // let's echo the class we just chose from our array of classes:
| |
|
| |
|
| |
| echo "If we access the element at index $randomlySelectedClass, we find the element $classes[$randomlySelectedClass].
| |
| This will most likely change every time you refresh the page. It is possible the same index will be chosen again.";
| |
|
| |
|
| |
| /*
| |
| </syntaxhighlight>
| |
|
| |
|
|
| |
|