I'm going crazy, spent a couple of hours trying different methods in replace values in arrays, but I can't get it to work.
foreach($potentialMatches as $potentialKey)
{
$searchKeywordQuery = "SELECT keyword, id FROM picture WHERE id='$potentialKey'";
$searchKeywords = mysql_query($searchKeywordQuery) or die(mysql_error());
while ($searchKeyWordsRow = mysql_fetch_array($searchKeywords))
{
$keyword = $searchKeyWordsRow['keyword'];
$pictureKeywordArray[$searchKeyWordsRow['id']]['keywords'] = explode(",", $keyword);
$pictureKeywordArray[$searchKeyWordsRow['id']]['match'] = 4;
}
}
foreach($pictureKeywordArray as $key = > $picValue)
{
foreach($picValue['keywords'] as $key = > $picIdValue)
{
if ($picIdValue == $searchIdKey)
{
echo $picValue['match'];
$picValue['match']++;
echo $picValue['match'];
}
}
}
foreach($pictureKeywordArray as $key = > $picValue)
{
echo $picValue['match'];
}
I'm novice as you can see, When I echo the picValue['match'] in the foreach loop it gives me a correct value after "++". But then below when I call the array again it gives me the value of 4 instead of 5 as intended. Thanks in advance for any help with this.
Cause you work with the item copy in first case try $pictureKeywordArray[$key]['match'] instead of $picValue['match']
In that second foreach you need to call it by reference:
foreach($pictureKeywordArray as $key => &$picValue)
{ //^-- `&` makes it by reference
foreach($picValue['keywords'] as $key => $picIdValue)
{
if ($picIdValue == $searchIdKey)
{
echo $picValue['match'];
$picValue['match']++; //now updates what you want it to update
echo $picValue['match'];
}
}
}
foreach works on a copy of the data. You must use a reference to modify the original:
foreach ($foo as $i => &$f)
{
$f++;
}
unset($f); // important to do this if you ever want to reuse that variable later
Related
I'm trying to link the MySQL while loop into foreach loop using something like this :
if($something == true){
foreach($array as $arr){
} else {
while($row = mysql_fetch_array($mysql_query)){
}
// loop instructions
}
It looks so wrong, I know but you see what I am trying to do ?.. I want to grab data from array if $something was true, else then grab data from database
I had another solution idea and its to manually match the array with how $mysql_query works so I can use them both with while only, something like this :
if($something == true){
$mysql_query = array("username" => "$_GET['username']", "password" => "$_GET['password']");
} else {
$mysql_query = mysql_query("SELECT * FROM users WHERE usern......");
}
while($row = mysql_fetch_array($mysql_query)){
...
That's a second way to do it but it looks wrong as well because the first array is normal, I want to match that normal array with how mysql_query builds it so it can fit with the while loop
P.S. : I DO NOT want to repeat writing the loop instructions, I want them both to work with only one like I mentioned above
Put your processing into a function:
function process_data($data) {
// do stuff
}
if($something){
foreach($array as $arr){
process_data($arr);
}
} else {
while($row = mysql_fetch_array($mysql_query)){
process_data($row);
}
}
The other answers here are fine, but you'd be better served just to make sure that $array is a valid array regardless of something ... How about
if (!something){
$array = array();
while($row=mysql_fetch_array($mysql_query)) {$array[] = $row;}
}
foreach($array as $arr){
// do work
}
You'd probably get a better answer if you expanded the scope of what you've explained a bit. Without knowing what the something is and what the data is, plus the ultimate objective then it's hard to tell what kind of structure you should be using.
It seems to me that you could achieve this by just using a function, if the code inside the loop is the same. Like this:
if($something == true)
{
foreach($array as $arr)
{
doWork($arr);
}
}
else
{
while($row = mysql_fetch_array($mysql_query))
{
doWork($row);
}
}
function doWork($arr)
{
//...
}
You cannot nest loop instructions inside a loop like this. You'll need to have two separate loops completely inside the IF statements.
if($something == true){
foreach($array as $arr){
// do work
}
} else {
while($row = mysql_fetch_array($mysql_query)){
// do work
}
}
Maybe you could look at from this viewpoint. And take note that this code uses mysql_fetch_assoc() instead of mysql_fetch_array(). Try both functions and look at the resulting rows with var_dump(). You will see that mysql_fetch_array() has twice as much data. You may want that, but probably not.
if ($something !== true)
{
$array = array();
while($row = mysql_fetch_assoc($mysql_query_result_resource))
{
$array[] = $row;
}
}
foreach($array as $arr)
{
/* PROCESS */
}
I have problem in deleting an element of array. Look:
<?php
session_start();
$i = 0;
$expected = $_GET['name'];
foreach($_SESSION['chart'] as $name)
{
if($name==$expected)
{
break;
}
$i++;
}
unset($_SESSION['chart'][$i]);
echo count($_SESSION['chart'])." ".$expected." ".$i;
//echo "<script>history.go(-1);</script>";
?>
I'm getting this output: 3 name 2.
I know that element in array exists with name 'name', but I can't unset it. Please help me.
Why not let PHP do the search?
<?php
session_start();
$key = array_search($_GET['name'], $_SESSION['chart']);
if ($key !== false) {
unset($_SESSION['chart'][$key]);
}
because you call unset out of foreach
try :
foreach($_SESSION['chart'] as $name)
{
if($name==$expected)
{
unset($name);
}
$i++;
}
You can make your intent clearer by using this form of foreach
foreach($_SESSION['chart'] as $idx=>$name)
{
if($name==$expected)
{
unset($_SESSION['chart'][$idx]);
break;
}
}
However, Till Helge Helwig's solution is better for this particular problem, but it's worth being aware that you don't need to maintain your own 'key' variable when using foreach.
Hi I have a PHP array with a variable number of keys (keys are 0,1,2,3,4.. etc)
I want to process the first value differently, and then the rest of the values the same.
What's the best way to do this?
$first = array_shift($array);
// do something with $first
foreach ($array as $key => $value) {
// do something with $key and $value
}
I would do this:
$firstDone = FALSE;
foreach ($array as $value) {
if (!$firstDone) {
// Process first value here
$firstDone = TRUE;
} else {
// Process other values here
}
}
...but whether that is the best way is debatable. I would use foreach over any other method, because then it does not matter what the keys are.
Here is one way:
$first = true;
foreach($array as $key => $value) {
if ($first) {
// something different
$first = false;
}
else {
// regular logic
}
}
$i = 0;
foreach($ur_array as $key => $val) {
if($i == 0) {
//first index
}
else {
//do something else
}
$i++;
}
I would do it like this if you're sure the array contains at least one entry:
processFirst($myArray[0]);
for ($i=1; $i<count($myArray); $1++)
{
processRest($myArray[$i]);
}
Otherwise you'll need to test this before processing the first element
I've made you a function!
function arrayCallback(&$array) {
$callbacks = func_get_args(); // get all arguments
array_shift($callbacks); // remove first element, we only want the callbacks
$callbackindex = 0;
foreach($array as $value) {
// call callback
$callbacks[$callbackindex]($value);
// make sure it keeps using last callback in case the array is bigger than the amount of callbacks
if(count($callbacks) > $callbackindex + 1) {
$callbackindex++;
}
}
}
If you call this function, it accepts an array and infinite callback arguments. When the array is bigger than the amount of supplied functions, it stays at the last function.
You can simply call it like this:
arrayCallback($array, function($value) {
print 'callback one: ' . $value;
}, function($value) {
print 'callback two: ' . $value;
});
EDIT
If you wish to avoid using a function like this, feel free to pick any of the other correct answers. It's just what you prefer really. If you're repeatedly are planning to loop through one or multiple arrays with different callbacks I suggest to use a function to re-use code. (I'm an optimisation freak)
In php I am converting posted data from a form to objects like this:
<?php
...some code...
$post = new stdClass;
foreach ($_POST as $key => $val)
$post->$key = trim(strip_tags($_POST[$key]));
?>
Then in my page I just echo posted data like this :
<?php echo $post->Name; ?>
<?php echo $post->Address; ?>
etc...
This works fine but I have multiple checkboxes that are part of a group and I echo the results of that, like this:
<?php
$colors = $_POST['color_type'];
if(empty($colors))
{
echo("No color Type Selected.");
}
else
{
$N = count($colors);
for($i=0; $i < $N; $i++)
{
echo($colors[$i] . ", ");
}
}
?>
That works when I am just using array, but how do I write this as object syntax?
using your code
function array_to_object($arr) {
$post = new stdClass;
foreach ($arr as $key => $val) {
if(is_array($val)) {
$post->$key = post_object($val);
}else{
$post->$key = trim(strip_tags($arr[$key]));
}
}
return $post;
}
$post = array_to_object($_POST);
or more complex solution
function arrayToObject($array) {
if(!is_array($array)) {
return $array;
}
$object = new stdClass();
if (is_array($array) && count($array) > 0) {
foreach ($array as $name=>$value) {
$name = strtolower(trim($name));
if (!empty($name)) {
$object->$name = arrayToObject($value);
}
}
return $object;
}
else {
return FALSE;
}
}
from http://www.richardcastera.com/blog/php-convert-array-to-object-with-stdclass
why would you want that? What's wrong with an array?
Use Object Oriented Programming, which might be what you are looking for. Treat it as an object, by making a class called Color and doing $colors[$i] = new Color();
This way you can do whatever you want with it, and add functions to it.
Pretty simple -- when you attach the color_type key to your object, it'll become an array that's a property of your object. This is most likely what you want: you probably won't want to turn that array into its own stdClass-based object, because then you won't be able to iterate through all the values (as easily). Here's a snippet:
<?php
// putting in both of these checks prevents you from throwing an E_WARNING
// for a non-existent property. E_WARNINGs aren't dangerous, but it makes
// your error messages cleaner when you don't have to wade through a bunch
// of E_WARNINGS.
if (!isset($post->color_type) || empty($post->color_type)) {
echo 'No colour type selected.'; // apologies for the Canadian spelling!
} else {
// this loop does exactly the same thing as your loop, but it makes it a
// bit more succinct -- you don't have to store the count of array values
// in $N. Bit of syntax that speeds things up!
foreach ($post->color_type as $thisColor) {
echo $thisColor;
}
}
?>
Hope this helps! Of course, in a real-life setting, you'll want to do all sorts of data validation and cleaning -- for instance, you'll want to check that the browser actually passed an array of values for $_POST['color_type'], and you'll want to clean the output in case someone is trying to inject an exploit into your page (by going echo htmlspecialchars($thisColor); -- this turns all characters like < and > into HTML entities so they can't insert JavaScript code).
I have a question about arrays and foreach.
If i have an array like this:
$test_arr = array();
$test_arr['name1'] = "an example sentence";
$test_arr['anything'] = "dsfasfasgsdfg";
$test_arr['code'] = "4334refwewe";
$test_arr['empty1'] = "";
$test_arr['3242'] = "";
how can I do a foreach and "pick" only the ones that have values? (in my array example, would only take the first 3 ones, name1, anything and code).
I tried with
foreach ($test_arr as $test) {
if (strlen($test >= 1)) {
echo $test . "<br>";
}
}
but it doesn't work. Without the "if" condition it works, but empty array values are taken into consideration and I don't want that (because I need to do a <br> after each value and I don't want a <br> if there is no value)
Sorry if I don't explain myself very well, I hope you understand my point. Shouldn't be too difficult I guess..
Thanks for your help !
Maybe will work
foreach ($test_arr as $test) {
if (strlen($test)!=="") {
echo $test . "<br>";
}
}
Your solution with corrected syntax:
foreach ($test_arr as $test) {
if (strlen($test)>=1) {
echo $test . "<br>";
}
}
Since empty strings are false, you could just do this (but you'd exclude 0's with the if):
foreach ($test_arr as $key => $val) {
if ($val) {
echo $val. "<br>";
}
}
If it has to be an empty string then (excluding 0 and FALSE):
foreach ($test_arr as $key => $val) {
// the extra = means that this will only return true for strings.
if ($val !== '' ) {
echo $val. "<br>";
}
}
Since it looks like you're using an associative array, you should be able to do this:
foreach( $test_arr as $key => $value )
{
if( $value != "" )
{
echo $value . "<br />";
}
}
As shown, you can test $value for an empty string directly. Since this is precisely the test you are trying to accomplish, I would hope that this would solve your problem perfectly.
On another note, this is pretty straight forward and should be very maintainable in the future when you've forgotten exactly what it was that you were doing!
You are better off to use a while loop like this:
while(list($test_key, $test_value) = each($test_arr))
{
if($test_value != "") { echo $test_value . "<br/>"; }
}
reset($test_arr);
If your array gets large, the while will be much faster. Even on small arrays, I have noticed a big difference in the execution time.
And if you really don't want the array key. You can just do this:
while(list(, $test_value) = each($test_arr))
{
if($test_value != "") { echo $test_value . "<br/>"; }
}
reset($test_arr);
You can check if the value is emtpy with empty().
Note that values like 0 or false are considered empty as well, so you might have to check for string length instead.
just a simple typing error:
foreach ($test_arr as $test) {
if (strlen($test) >= 1) {
echo $test . "<br>";
}
}
Try this:
foreach ($test_arr as $test) {
if (strlen($test) > 0) {
echo $test . "<br>";
}
}