- Listing of String Functions
- Using the String Functions
- Formatting Strings
- Converting to and from Strings
- Creating Arrays
- Modifying Arrays
- Removing Array Elements
- Looping Over Arrays
- Listing of the Array Functions
- Sorting Arrays
- Navigating through Arrays
- Imploding and Exploding Arrays
- Extracting Variables from Arrays
- Merging and Splitting Arrays
- Comparing Arrays
- Manipulating the Data in Arrays
- Creating Multidimensional Arrays
- Looping Over Multidimensional Arrays
- Using the Array Operators
- Summary
This chapter is from the book
This chapter is from the book
This chapter is from the book
Modifying Arrays
After you've created an array, what about modifying it? No problem—you can modify the values in arrays as easily as other variables. One way is to access an element in an array simply by referring to it by index. For example, say you have this array:
$fruits[1] = "pineapple"; $fruits[2] = "pomegranate"; $fruits[3] = "tangerine";
Now say you want to change the value of $fruits[2] to "watermelon". No problem at all:
$fruits[1] = "pineapple"; $fruits[2] = "pomegranate"; $fruits[3] = "tangerine"; $fruits[2] = "watermelon";
Then say you wanted to add a new element, "grapes", to the end of the array. You could do that by referring to $fruits[], which is PHP's shortcut for adding a new element:
$fruits[0] = "pineapple"; $fruits[1] = "pomegranate"; $fruits[2] = "tangerine"; $fruits[2] = "watermelon"; $fruits[] = "grapes";
All that's left is to loop over the array and display the array contents, as shown in Example 3-1, phparray.php.
Example 3-1. Modifying an array's contents, phparray.php
<HTML>
<HEAD>
<TITLE>
Modifying an array
</TITLE>
</HEAD>
<BODY>
<H1>
Modifying an array
</H1>
<?php
$fruits[0] = "pineapple";
$fruits[1] = "pomegranate";
$fruits[2] = "tangerine";
$fruits[2] = "watermelon";
$fruits[] = "grapes";
for ($index = 0; $index < count($fruits); $index++){
echo $fruits[$index], "<BR>"; }
?>
</BODY>
</HTML>
The results appear in Figure 3-1. As you can see, we not only were able to modify $fruits[2] successfully but were also able to add "grapes" to the end of the array.
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Figure 3-1 Modifying an array.
You can also copy a whole array at once if you just assign it to another array:
<?php
$fruits[0] = "pineapple";
$fruits[1] = "pomegranate";
$fruits[2] = "tangerine";
$fruits[2] = "watermelon";
$fruits[] = "grapes";
$produce = $fruits;
echo $produce[2];
?>
This script gives you this output:
watermelon