I have an array that can have any number of items inside it, and I need to grab the values from them at a certain pattern.
It's quite hard to explain my exact problem, but here is the kind of pattern I need to grab the values:
No
Yes
No
No
No
Yes
No
No
No
Yes
No
No
I have the following foreach() loop which is similar to what I need:
$count = 1;
foreach($_POST['input_7'] as $val) {
if ($count % 2 == 0) {
echo $val;
echo '<br>';
}
$count ++;
}
However, this will only pick up on the array items that are 'even', not in the kind of pattern that I need exactly.
Is it possible for me to amend my loop to match that what I need?
You can do this much simpler with a for loop where you set the start to 1 (the second value) and add 4 after each iteration:
for ($i = 1; $i < count($_POST['input_7']); $i += 4) {
echo $_POST['input_7'][$i] . '<br />';
}
Example:
<?php
$array = array(
'foo1', 'foo2', 'foo3', 'foo4', 'foo5',
'foo6', 'foo7', 'foo8', 'foo9', 'foo10',
'foo11', 'foo12', 'foo13', 'foo14', 'foo15'
);
for ($i = 1; $i < count($array); $i += 4) {
echo $array[$i] . '<br />';
}
?>
Output:
foo2foo6foo10foo14
DEMO
Try this:
$count = 3;
foreach($_POST['input_7'] as $val) {
if ($count % 4 == 0) {
echo $val;
echo '<br>';
}
$count ++;
}
Related
Here is my code, and it is not removing $arr[5] element so that I am trying to remove strings starting with # from my array
this is code
<?php
$arr = [
'#EXTM3U',
'#EXTINF:177,Paul Dateh & Oren Yoel - Be More',
'Be More.mp3',
'#EXTINF:291,Christopher Toy - Just Because',
'Just Because.mp3',
'#EXTINF:238,Magnetic North - Drift Away',
'Drift Away.mp3'
];
for ($i = 0; $i <= count($arr); $i++) {
if ($arr[$i]{0} == '#') {
echo $arr[$i] . "\n";
unset($arr[$i]);
}
}
print_r($arr);
?>
Reason:- You are counting array length inside the loop and every time when any value got unset() from the array, length of array decreased and value of count($array) changed (simply decreased)
So logically your 5th and 6th element never goes through if condition (they never get traversed by loop because of decreasing length of the array )
Solution 1:- Put count outside and it will work properly:-
$count = count($arr);
//loop start from 0 so use < only otherwise, sometime you will get an undefined index error
for ($i = 0; $i < $count; $i++) {
if ($arr[$i]{0} == '#') {
//echo $arr[$i] . "\n";
unset($arr[$i]);
}
}
print_r($arr);
Output:-https://eval.in/996494
Solution 2:- That's why i prefer foreach() over for() loop
foreach($arr as $key=> $ar){
if ($ar[0] == '#') {
unset($arr[$key]);
}
}
print_r($arr);
Output:-https://eval.in/996502
more spacific :
for ($i = 0; $i < count($arr); $i++) {
if (strpos($arr[$i], '#') !== false) {
echo "<br/>";
} else {
echo $arr[$i]."<br/>";
}
}
Try to use additional array to push right values. You calc count($arr); each iteration and when you do count($arr); your array gets smaller and count($arr); returns smaller values, so last elements won't be comparing, try to use variable to calc count before loop make changes:
<?php
//...
$start_count = count($arr);
for ($i = 0; $i <= $start_count; $i++) {
if ($arr[$i]{0} == '#') {
echo $arr[$i] . "\n";
unset($arr[$i]);
}
}
Or remove bad element with a help of additional array, put good elements in new array and don't delete them from input array:
<?php
$arr = [
'#EXTM3U',
'#EXTINF:177,Paul Dateh & Oren Yoel - Be More',
'Be More.mp3',
'#EXTINF:291,Christopher Toy - Just Because',
'Just Because.mp3',
'#EXTINF:238,Magnetic North - Drift Away',
'Drift Away.mp3'
];
$cleared_from_mess_array = array();
for ($i = 0; $i <= count($arr); $i++) {
if ($arr[$i]{0} != '#')
{
array_push($cleared_from_mess_array,$arr[$i]);
}
}
print_r($cleared_from_mess_array);
exit;
I'm trying to output my array results in groups of 4.
<?php for ($i = 0; $i < 4; ++$i) { ?>
<div>
// code
</div>
<?php } ?>
The above does 4, but obviously doesn't re-loop.
You can loop whole array and group you output with help of "%" operator.
<div>
<?php for ($i = 0; $i < count($array); $i++) {
if (($i % 4) == 0) {
echo "</div><div>";
}
echo "Element " . $array[$i]; // CODE
}
</div>
Other than using Mod as the other answers show, you could use array_chunk() to create the groups:
$groups = array_chunk($original_array, 4);
foreach($groups as $group){
echo '<div>';
foreach($group as $item){
echo $item;
}
echo '</div>';
}
You can use a while loop to reloop for the whole results to be printed
<?php while(conditions) {
for ($i = 0; $i < 4; ++$i) { ?>
<div>
// code
</div>
<?php } } ?>
Try this that way you can jump by 4
for ($i = 0; $i < 20; $i = $i+4) {
echo $i.'<br/>';
}
I would use a foreach and then just throw in an extra check to output the divs.
$i=0;
foreach ($array as $key->$val)
{
if($i%3==0)
{
echo "<div>";
}
// your stuff
if($i%3==0)
{
echo "</div>";
}
$i++;
}
array_slice() returns the sequence of elements from the array array as specified by the offset and length parameters.
you can check out from here http://php.net/manual/en/function.array-slice.php
try this, use nested for loop, this will loop 4 times. You can try to integrate with your code. If
for ($i = 0; $i < 4; $i++){
for($j = 0; $j < 4; $j++){
echo $a[$j++];
}
echo "<br/>";
}
I hope it can help you.
you can try $i++, because you use ++$i in this way "for" works 3 times!
for ($i = 0; $i < 4; $i++)
I want to print integer in triangle form which look like this
1
121
12321
I tried this but I do not get the actual result
for($i=1;$i<=3;$i++)
{
for($j=3;$j>=$i;$j--)
{
echo " ";
}
for($k=1;$k<=$i;$k++)
{
echo $k;
}
if($i>1)
{
for($m=$i; $m>=1; $m--)
{
echo $m;
}
}
echo "<br>";
}
Output of this code is:
1
1221
123321
Where am I going wrong, please guide me.
Another integer solution:
$n = 9;
print str_pad ("✭",$n," ",STR_PAD_LEFT) . PHP_EOL;
for ($i=0; $i<$n; $i++){
print str_pad ("", $n - $i);
for ($ii=-$i; $ii<=$i; $ii++){
if ($i % 2 != 0 && $ii % 2 == 0)
print "&#" . rand(10025,10059) . ";";
else print $i - abs($ii) + 1;
}
print PHP_EOL;
}
✭
1
1✬1
12321
1❊3✪3✳1
123454321
1✼3✶5❃5❈3✸1
1234567654321
1✾3✯5✿7❉7✫5✷3✶1
12345678987654321
Or if you already have the string, you could do:
$n = 9; $s = "12345678987654321"; $i = 1;
while ($i <= $n)
echo str_pad ("", $n-$i) . substr ($s,0,$i - 1) . substr ($s,-$i++) . PHP_EOL;
Your code should be this:
for($i=1;$i<=3;$i++)
{
for($j=3;$j>$i;$j--)
{
echo " ";
}
for($k=1;$k<$i;$k++) /** removed = sign*/
{
echo $k;
}
if($i>=1) /**added = sign*/
{
for($m=$i; $m>=1; $m--)
{
echo $m;
}
}
echo "<br>";
}
Try this.
Details:
Your loop is not proper as in case of for($k=1;$k<=$i;$k++), this will print the
repeated number when check the condition for less then and again for equals to.
So remove the equals sign.
reason to add the eqaul sign in if($i>=1) is that the first element will not print if there will not be equals as first it will be print by for loop from where removed the equal sign.
Your output will be this:
1
121
12321
For all the x-mas lovers:
$max = 9; # can be 2 .. 9
for($i = 1; $i <= $max; $i++) {
$line = (str_pad('', $max - $i));
for($ii = 1; $ii <= $i; $ii++) {
$line .= $ii;
}
for($ii = $i-1; $ii > 0; $ii--) {
$line .= $ii;
}
echo $line . PHP_EOL;
}
Output:
1
121
12321
1234321
123454321
12345654321
1234567654321
123456787654321
12345678987654321
Amazing what computers are able to achieve nowadays! Isn't it?
A little late to the party, but here's yet another solution that uses a "for" loop with two initialization variables and a ternary-based incrementer/decrementer. It's an unorthodox use of a "for" loop, but it's still perfectly valid and arguably makes the code more elegant and easier to follow. I chose to add space before and after each semicolon and omit all other space inside the parentheses so it's easier to visualize each of the three pieces of the "for" loop (initialization, condition, increment/decrement):
$count = 9;
echo "<pre>";
for ($i=1; $i<=$count; $i++) {
echo str_pad("",$count-$i," ",STR_PAD_LEFT);
for ( $j=1,$up=true ; $j>0 ; $up?$j++:$j-- ) {
echo $j;
if ($j==$i) {$up = false;}
}
echo "<br>";
}
echo "</pre>";
Output:
1
121
12321
1234321
123454321
12345654321
1234567654321
123456787654321
12345678987654321
I have following for loop code in PHP
for($i=10; $i<=50; $i=$i+10)
{
echo $i;
}
it will print
10 20 30 40 50
I want to add some specific $i value such as
$i=15 and $i=28
So it shold print
10 15 20 28 30 40 50
How should I edit the code ?
If you want specific values, you should make an array with those values and iterate through it:
$vals = array(10, 15, 20, 28, 30, 40, 50);
foreach ($vals as $i) {
echo $i;
}
if you have fixed place where to show these values .. then you can use simple if
for($i=10; $i<=50; $i=$i+10)
{
echo $i;
if($i == 10)
{
echo '15';
}
if($i == 20)
{
echo '28';
}
}
Ok, i'll play the "interview question" game :
for($i=10; $i<=50; $i++) {
if ($i % 10 === 0) {
echo $i;
}
else if ($i === 15 || $i === 28) {
echo $i;
}
}
Result at http://codepad.org/JBPkm8W1
You can improve this answer by adding an "allowed values" table :
$allowed = array (15, 28); // List here all the non % 10 value you want to print
for($i=10; $i<=50; $i++) {
if ($i % 10 === 0) {
echo $i;
}
else if (in_array($i, $allowed)) {
echo $i;
}
}
The result at http://codepad.org/w8Erv17K
The easiest way is to use a foreach loop like #WaleedKhan wrote.
To prepare the array you can use for loop like you did:
$vals = array();
for($i = 10; $i <= 50; $i = $i + 10){
$vals[] = $i;
}
$vals[] = 15;
$vals[] = 28;
sort($vals);
foreach(...
Try this :
$extra = array(15,28);
$res = array();
for($i=10; $i<=50; $i=$i+10){
$res[] = $i;
}
$result = array_merge($res,$extra);
sort($result);
echo "<pre>";
print_r($result);
You can put the 15 and 28 values in array and get the values using array_intersect.
Create an array to hold the 15 and 28 values (intermeditate values).
$new_vals = array(15,28);
Now in your for loop you can call array_insersect function to get the intermediate values. Your final code will look like this.
$new_vals = array(15,28);
for($i=10; $i<=50; $i=$i+10)
{
echo $i;
$val_range = range($i,$i+10);
$new_array = array_intersect($new_vals , $val_range);
foreach($new_array as $value)
{
echo $value;
}
}
You could do something like this:
function EchoLoopStuff($start, $to, $step) {
for($i=$start; $i<=$to; $i=$i+$step) {
echo $i;
}
}
But you'd need to add some checking to save yourself from issues when inputs contradict.
Here's the issue:
I retrieve the following data string from my database:
$row->exceptions = '1,2,3';
After explode I need the below code to check each one of the exploded pieces
$exceptions = explode(",", $row->exceptions);
//result is
//[0] => 1
//[1] => 2
//[2] => 3
for ($i = 0; $i <= $row->frequency; $i++) {
if ($exceptions[] == $i) {
continue;
} else {
//do something else
}
}
How can I make $exceptions[] loop through all keys from the exploded array so it evaluates if ==$i?
Thanks for helping.
It should suffice to substitute:
if($exceptions[] == $i)
with:
if(in_array($i,$exceptions))
By the way, it eliminates the need for a nested loop.
Ah, should be straightforward, no?
$exceptions = explode(",", $row->exceptions);
for ($i = 0; $i <= $row->frequency; $i++) {
foreach($exceptions as $j){
if($j == $i){
// do something
break;
}
}
}
I think I understand what you are asking. Here's how you would test within that loop whether the key equals $i.
for ($i = 0; $i <= $row->frequency; $i++)
{
foreach ($exceptions as $key => $value)
{
if ($key == $i)
{
continue;
}
}
}