I have a pretty simple indexed array:
Array
(
[0] => 1
[1] => Buster Posey
[2] => SF
[3] => C
[4] => 16.60
[5] => 5
[6] => 28
[7] => 2
[8] => Joe Mauer
[9] => Min
[10] => C
[11] => 57.60
[12] => 35
[13] => 80
...
I need to add every 2nd, 3rd and 5th key value to $str
.
I can handle operating on the $str
, but I can't wrap my tiny little brain around the loop(s)/counter(s) I need, so just a nudge in the right direction would be great.
For clarity, the result of my $str
given the above array would look something like this:
Buster Posey, SF, 16.60
Joe Mauer, Min, 57.60
That's the 2nd, 3rd and 5th element of the array with a couple commas and a newline added in for good measure repeated all the way down the array.
EDIT:
I have an error with my question. The comment by salathe below is correct. They're in groups of seven, so I need every 2nd, 3rd and 5th element, then skip 2 and start the process over. I'm going to use array_chunk , as suggested. Thanks for all of the answers.
Something like this?
$i = 0;
foreach($array as $value) {
if ($i++ % 2 == 0 || $i++ % 3 == 0 || $i++ % 5 == 0) {
echo $value;
}
}
You need to use the modulo operator ( %
). It returns the remainder of the division of a number, and is routinely used to check if a number is a multiple of another.
So, to check is a number is even ( exactly divisible by 2 ), you do
$odd = $number%2;
To make it a complete answer, you use this criteria inside a loop (don't know how to do so without one) :
for($i=0; $i<count($array)-1;$i++){
if($i%5==0) { $str .= $array[$i]; }
}
Two different approaches: loop over all entries and use mod, or loop for each different condition.
All in one loop:
foreach ($array as $k => $v){
if ($k % 2 == 0 || $k % 3 == 0 || $k % 5 == 0){
.. do something with $v
}
}
Different loops:
for ($i=0; $i<count($array); $i+=2) .. do something with $array[$i]
for ($i=0; $i<count($array); $i+=3) .. do something with $array[$i]
for ($i=0; $i<count($array); $i+=5) .. do something with $array[$i]
You need to take sequences with steps 2-1-2, 2-1-2. You can do this with double loop,loop + case...
I don't quite know PHP, but if I understand correctly, you need to concatenate the indexes 2, 3, 5 and perhaps more, following a progression:
n[0] = 2
n[1] = 3
n[2] = 5
...
n[i] = n[i-1] + n[i-2]
So you might need to create an array of the indexes you need to concatenate, providing the first two values (looks like a Fibonacci series to me):
n[0] = 2;
n[1] = 3;
for(i=2, i<m, i++) {
n[i] = n[i-1] + n[i-2];
}
Then, you can use this array to concatenate the desired values from your array:
for(i=0; i<m; i++) {
str = concatenate(str, arr[n[i]]);
}
(I know the syntax is not PHP... but I think it illustrates the idea)
If you need a different progression, you need to answer this question: how do I calculate the next value, using the previous value(s)? Then you can build an algorithm that makes the work.
Hope this helps you.
foreach( array_chunk( $array, 7) as $row) {
echo $row[1] . ' , ' . $row[2] . ' , ' . $row[4] . "\n";
}
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