Integrating PHP custom made functions for use with "FOR" loops. 1. Create a function for adding 5 to any number while counting from 1  10. function Add_Five($num) { $x = $num + 5; return($x); } $x = ""; for($i=1;$i<11;$i++) { $x .= Add_Five($i)."  "; } echo $x; produces: 6  7  8  9  10  11  12  13  14  15 You can easily combine many custom functions with loops of all kinds. 2. Add 5, using the function Add_Five(), to an array of numbers. function Add_Five($num) { $x = $num + 5; return($x); }
$numbers = array(1,4,22,11,21,34,93);
$count = count($numbers);
$x = "";
for($i=0;$i<$count;$i++) { $x .= Add_Five($numbers[$i])."  "; } echo $x; produces: 6  9  27  16  26  39  98
You can see that whatever the array of numbers you start with (which may be unknown), you can interact with that array and put each element of that array through a function. You first count the number of elements in that array with count(), a builtin PHP function for counting those elements. Then you can use a FOR loop to interact with each element (number) that exists in that array.
