Arrays are common to many programing languages. They are special variables which can hold more than one value, each stored in its own numbered 'space' in the array. Arrays are extremely useful, especially when using WHILE loops.
Setting Up An Array
Setting up an array is slightly different to setting up a normal variable. In this example I will set up an array with 5 names in it :
$names[0] = 'John';
$names[1] = 'Paul';
$names[2] = 'Steven';
$names[3] = 'George';
$names[4] = 'David';
$names[1] = 'Paul';
$names[2] = 'Steven';
$names[3] = 'George';
$names[4] = 'David';
As you can see, the parts of an array are all numbered, starting from 0. To add a value to an array you must specify the location in the array by putting a number in [ ].
Reading From An Array
Reading from an array is just the same as putting information in. All you have to do is to refer to the array and the number of the piece of data in the array. So if I wanted to print out the third name I could use the code:
echo "The third name is $names[2]";
Which would output:
The third name is Steven
Using Arrays And Loops
One of the best uses of a loop is to output the information in an array. For instance if I wanted to print out the following list of names:
Name 1 is John
Name 2 is Paul
Name 3 is Steven
Name 4 is George
Name 5 is David
Name 2 is Paul
Name 3 is Steven
Name 4 is George
Name 5 is David
I could use the following code:
$number = 5;
$x = 0;
while ($x < $number) {
$namenumber = $x + 1;
echo "Name $namenumber is $names[$x]<br>";
++$x;
}
$x = 0;
while ($x < $number) {
$namenumber = $x + 1;
echo "Name $namenumber is $names[$x]<br>";
++$x;
}
As you can see, I can use the variable $x from my loop to print out the names in the array. You may have noticed I am also using the variable $namenumber which is always 1 greater than $x. This is because the array numbering starts from 0, so to number the names correctly in the output I must add one to the actual value.











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