Does anyone know why this doesn't work
function my_current($array) {
return current($array);
}
$array = array(1,3,5,7,13);
while($i = my_current($array)) {
$content .= $i.',';
next($array);
}
yet this does
$array = array(1,3,5,7,13);
while($i = current($array)) {
$content .= $i.',';
next($array);
}
or how to make the top one work?
It's a little question but it would be a big help!
Thanks
Richard
The array is copied, which means that the current pointer is lost. Pass it as a reference.
function my_current(&$array) {
Or better yet, use implode().
By default a copy of the array is being made.
Try this:
function my_current(&$array) {
return current($array);
}
I guess it's because when you call a function with an array parameter, the array is copied over. Try using references.
function my_current(&$array) {
return current($array);
}
Notice the &.
Related
I have an small piece of PHP code that needs to put every file in the current directory into an array.
I have done this by making reading the dir with glob() and when it meets another dir it will loop.
My code I have as of now:
<?php
$find = '*';
$result = array();
function find($find)
{
foreach (glob($find) as $entry)
{
$result[] = $entry;
echo $entry.'<br>';
if (is_dir($entry)){
$zoek = ''.$entry.'/*';
find($zoek);
}
}
return $result;
}
print_r(find($find));
?>
When I execute the code the echo print exactly what I want. But the printed array doesn't give me the values I want, it only gives the values in the first dir it will come by then it seems to stop adding the value in the array.
What am I doing wrong?
You need to actually preserve the results you produce in the recursive callings to your function:
<?php
function listNodesInFolder($find) {
$result = [];
foreach (glob($find) as $entry) {
$result[] = $entry;
if (is_dir($entry)) {
$result = array_merge($result, find($entry.'/*'));
}
}
return $result;
}
print_r(find('*'));
Once on it I also fixes a few other issues with your code:
$result should be declared as an array inside your function, that that even if it does not loop you still return an array and not something undefined.
indentation and location of brackets got adjusted to general coding standards, that makes reading your code much easier for others. Get used to those standards, it pays out, you will see.
no need for an extra variable for the search pattern inside the conditional.
a speaking name for the function that tells what it actually does.
you should not name variables and functions alike ("find").
You need to add the result of find() to the array
Edit added array_merge - Cid's idea
<?php
$find = '*';
function find($find)
{
$result = array();
foreach (glob($find) as $entry)
{
$result[] = $entry;
echo $entry.'<br>';
if (is_dir($entry)){
$zoek = ''.$entry.'/*';
$result = array_merge($result, find($zoek));
}
}
return $result;
}
print_r(find($find));
?>
i have created an array using php something like this
$array1=array()
for($i=0;$i<5;$i++)
{
$array1[$i]=somevalue;
for($y=0;$y<$i;$y++)
{
print_r($array1[$y]);
}
}
it does not print the value.
If nothing else, you should move the inner loop out:
for($i=0;$i<5;$i++)
{
$array1[$i]=somevalue;
}
for($y=0;$y<5;$y++)
{
print_r($array1[$y]);
}
I just ran this code, the only change i made was putting a semicolon in the first line ;)
<?php
$array1=array();
for($i=0;$i<5;$i++)
{
$array1[$i]="abcd";
for($y=0;$y<$i;$y++)
{
print_r($array1[$y]);
}
}
?>
Output:
abcdabcdabcdabcdabcdabcdabcdabcdabcdabcd
Based on #Jon's answer:
$array1 = array();
for($i=0;$i<5;$i++)
{
$array1[$i]=somevalue;
}
$count = count($array1);
for($y=0;$y<$count;$y++)
{
print_r($array1[$y]);
}
You can put the count function in the for loop, but that's bad practice. Also, if you are trying to get the value of EVERY value in the array, try a foreach instead.
$array1 = array();
for($i=0;$i<5;$i++)
{
$array1[$i]=somevalue;
}
foreach($array1 as $value)
{
print_r($value);
}
Because of the way how print_r works, it is silly to put it inside a loop, this will give you actual output and is error free :).
$array1=array();
for($i=0;$i<5;$i++)
{
$array1[$i]='somevalue';
}
print_r($array1);
for($y=0;$y<$i;$y++)
Your display loop isn't displaying the entry you've just added as $array[$i], because you're looping $y while it's less than $i
for($y=0;$y<=$i;$y++)
At the risk of self-embarrassment, could anyone tell me how to use return here:
function dayCount() {
for ($dayBegin = 1; $dayBegin < 32; $dayBegin++)
{
"<option value=\"".$dayBegin."\">".$dayBegin."</option>";
}
}
My issue is that I am passing this function to Smarty via
$dayCount = dayCount();
$smarty->assign('dayCount', $dayCount);
and
{$dayCount}
but instead the HTML is going straight to the buffer, right before <html> (thanks Hamish), not inside the HTML element I want.
Any help on this?
You need to build up the return statement
function dayCount() {
$return = array();
for ($dayBegin = 1; $dayBegin < 32; $dayBegin++)
{
$return[] = "<option value=\"".$dayBegin."\">".$dayBegin."</option>";
}
return $return;
}
Although this is building up an array like you asked. When outputting it, you would need to implode it.
implode('', $dayCount);
Or otherwise, build up a string instead of an array.
I am in the middle of building a cache layer for the Redis DB to my application and I have come to the point where's it's about to take care of arrays.
I wonder if there's any good (high performance!) way of controlling an string to be serialized or not with PHP?
Thanks a lot!
$array = #unserialize($string);
if ($array === false && $string !== 'b:0;') {
// woops, that didn't appear to be anything serialized
}
The $string !== 'b:0;' checks to see if the serialized string may have been the value false. If this check is important to you you may want to trim the serialized string or otherwise preprocess it to make sure this works.
For those looking for alternative, this code worked for me as helper function for Laravel framework and then you can call it anywhere.
if(!function_exists('isSerialized')){
function isSerialized($string){
$tempString = '';
$array = #unserialize($string);
if(is_array($array)){
foreach ($array as $k=>$i){
//do something with data
$tempString .= $k . $i['something'];
}
} else {
$tempString = $string;
}
return $itemString;
}
}
I have the following PHP code which works out the possible combinations from a set of arrays:
function showCombinations($string, $traits, $i){
if($i >= count($traits)){
echo trim($string) . '<br>';
}else{
foreach($traits[$i] as $trait){
showCombinations("$string$trait", $traits, $i + 1);
}
}
}
$traits = array(
array('1','2'),
array('1','2','3'),
array('1','2','3')
);
showCombinations('', $traits, 0);
However, my problem is that I need to store the results in an array for processing later rather than just print them out but I can't see how this can be done without using a global variable.
Does anyone know of an alternative way to achieve something similar or modify this to give me results I can use?
Return them. Make showCombinations() return a list of items. In the first case you only return one item, in the other recursive case you return a list with all the returned lists merged. For example:
function showCombinations(...) {
$result = array();
if (...) {
$result[] = $item;
}
else {
foreach (...) {
$result = array_merge($result, showCombinations(...));
}
}
return $result;
}
In addition to the other answers, you could pass the address of an array around inside your function, but honestly this isn't nearly the best way to do it.
Using the variable scope modifier static could work. Alternatively, you could employ references, but that's just one more variable to pass. This works with "return syntax".
function showCombinations($string, $traits, $i){
static $finalTraits;
if (!is_array($finalTraits)) {
$finalTraits = array();
}
if($i >= count($traits)){
//echo trim($string) . '<br>';
$finalTraits[] = $string;
} else {
foreach($traits[$i] as $trait){
showCombinations("$string$trait", $traits, $i + 1);
}
}
return $finalTraits;
}
$traits = array(
array('1','2'),
array('1','2','3'),
array('1','2','3')
);
echo join("<br>\n",showCombinations('', $traits, 0));
Of course, this will work as expected exactly once, before the static nature of the variable catches up with you. Therefore, this is probably a better solution:
function showCombinations($string, $traits, $i){
$finalTraits = array();
if($i >= count($traits)){
$finalTraits[] = $string;
} else {
foreach($traits[$i] as $trait){
$finalTraits = array_merge(
$finalTraits,
showCombinations("$string$trait", $traits, $i + 1)
);
}
}
return $finalTraits;
}
although the solution by Lukáš is the purest as it has no side effects, it may be ineffective on large inputs, because it forces the engine to constantly generate new arrays. There are two more ways that seem to be less memory-consuming
have a results array passed by reference and replace the echo call with $result[]=
(preferred) wrap the whole story into a class and use $this->result when appropriate
the class approach is especially nice when used together with php iterators
public function pageslug_genrator($slug,$cat){
$page_check=$this->ci->cms_model->show_page($slug);
if($page_check[0]->page_parents != 0 ){
$page_checks=$this->ci->page_model->page_list($page_check[0]->page_parents);
$cat[]=$page_checks['re_page'][0]->page_slug;
$this->pageslug_genrator($page_checks['re_page'][0]->page_slug,$cat);
}
else
{
return $cat;
}
}
this function doesnt return any value but when i m doing print_r $cat it re
store the results in a $_SESSION variable.