Designing Solutions Through Programming block 1 Lesson Notes - October 12 2017: Difference between revisions
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By the end of class you should say: | By the end of class you should say: | ||
* I can | * I can define array | ||
* | |||
<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> | |||
</td> | </td> |
Latest revision as of 20:31, 12 October 2017
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