Lets say I have an array looking like this:
$sql = array("name"=>"Peter", "active"=>1 , "age"=>30)
and a loop looking like this:
for($i=0;$i<count($sql);$i++){
$value[$i] = ($sql[$i]);
echo $value[$i];
}
I want the loop to iterate through the array and assign each value to a new variable.
In this code i tried to make it store the values in:
value1
value2
value3
But sadly this doesnt work, thus I am here seeking help.
Or is it a problem that i got an associative array instead of a numeric one?
I dont want to use this loop on this array only but on other arrays with different keys and length aswell.
Edit: I think I may have not wrote it cleary enough to tell you what i want to achieve:
I want to have three string values at the end of the loop not stored in an array:
Variable1 should contain "Peter"
Variable2 should contain "1"
Variable3 should contain "30"
Plus I want this loop to be dynamic, not only accepting this specific array but if I were to give it an array with 100 Values, I would want to have 100 different variables in which the values are stored.
Sorry for not being clear enough, I am still new at stackoverflow.
Going by your condition, assign each value to a new variable, I think what you want would be to use Variable variables. Here is an example:
<?php
$sql = array("name"=>"Peter", "active"=>1 , "age"=>30);
$count = 1;
foreach ($sql as $value) {
$x = 'value'.$count;
$$x = $value; //here's the usage of Variable variables
$count++;
}
echo $value1.'<br/>';
echo $value2.'<br/>';
echo $value3.'<br/>';
I went to your sample variables ($value1, $value2, etc.). I also changed your loop to foreach to easily loop the array. And I also added a $count that will serve as the number of the $value variable.
The $count wouldn't be necessary if your index are numeric, but since its an associative array, something like this is needed to differentiate the variables created
A brief explanation as requested:
$x contains the name of the variable you want to create (in this case, value1), then when you add another $ to $x (which becomes $$x), you are assigning value to the current value of $x (this equals to $value1='Peter')
To dynamically define a variable use $$. Demo
$sql = array("name"=>"Peter", "active"=>1 , "age"=>30);
$index = 1;
foreach($sql as $value){
${"value" . $index++} = $value;
}
Related
I feel like i'm missing something quite simple. What are some of the best ways to iterate through combinations of $key names -- doing something different for each-- in a php foreach loop?
I have a number of values in an array with key values that follow the same naming format.
Example:
$rec_items['title3'] = implode($meta['title3']);
$rec_items['title4'] = implode($meta['title4']);
$rec_items['title5'] = implode($meta['title5']);
The $rec_items array also contains other values that do not follow this naming convention (or data type).
I'm looping through $rec_items with a foreach loop. I would like to be able to dynamically cycle through key names in $rec_items, and 'do something' when a key is found that matches title*. I've tried pushing numeric numbers from a counter variable into key names to be searched for (like below):
foreach ($rec_items as $key => $value){
$c = 0;
if(!empty($key[${'title'.$c}]){
$c++;
//do something
}
I believe that I cannot pass the value ${'title'.$c} into $key[] and have tried to pass the value of ${'title'.$c} as a string with no luck.
I just share the above to try to highlight what i'm trying to achieve.
(1) dynamically loop through key names in the format 'title*'
(2) if the key name is present in the $rec_items array ... do something.
I'm not sure what your original code was trying for; you appeared to be treating the array key like an array itself? Using a variable variable? Anyway, you just need a simple string search of the key. You can use regular expressions or whatever you like for more complex matching.
<?php
$rec_items = ["foo"=>12, "bar"=>34, "title1"=>56, "title2"=>78, "baz"=>90];
foreach ($rec_items as $k=>$v) {
if (strpos($k, "title") === 0) {
echo "$k = $v\n";
}
}
Output:
title1 = 56
title2 = 78
I have rows in my teams table named player1, player2, player3 ... player12. In PHP script i set them as variables ($player1,$player2...) and want to loop through them to check if they are NULL, and if they are not to count them.
How may I increment a variable in PHP? I have tried doing it likes this:
<?
$playerspicked = 0;
for($i = 1; $i <= 12; $i++) {
$playercheck = "$player"+$i;
if($playercheck != 0) {
$playerspicked++;
}
}
?>
but this wouldn't work.
You can do this with complex expressions (curly brackets {}) around a variable name.
if(empty(${"player$i"})) {
//player$i is empty
}
complex expressions allow you to set variable names dynamically.
To help you better understand how these work, I will show you that
you can also use these just like regular string concatenation like so
$variable = "many test";
echo "this is a test echo. {$variable}";
I commonly use this for generating a variable for many array variables based on their key
$array = array("key1" => "value1", "key2" => "value2");
foreach($array as $key => $value) {
${$key} = $value;
}
The code above would create 2 variables, $key1 and $key2, with the appropriate value associated with them.
Alternatively, I'm pretty sure you can just add another $ to the front of your variable, but I would say this is harder to read and figure out what's going on.
$playercheck = "player"+$i;
if($$playercheck != 0) {
$playerspicked++;
}
In your case there is a much easier way to count all the not null players in the team.
echo count(array_filter($yourTeam));
the array_filter function without a second parameter will automatically remove the null entries.
I want to get keys and values from a multi-dimensional array dynamically, to better explain what I'm trying to achieve please see the code below.
$i = 0;
foreach ($faq as $f) {
$q = 'faq'.$i;
$a = 'faq'.$i.'_answer';
echo $faq['faq1'][$i];
echo $faq['faq1_answer'][$i];
$i++;
}
The literal text above faq1 and faq1_answer needs to be replaced by the variable $q and $a respectively for me to be able to get the keys and values dynamically, but I cannot figure out how to add the variable.
The keys will always be the same, except for the number, which will change from 1 to 99. So with the code above, I can get the value of faq1 but I also need to grab the value of faq2 etc, hence why the variables above would work as I need.
tl;dr faq1 needs to be able to change to faq2 on the next iteration, hence the reason for me using $i.
Maybe like this?
$i = 0;
foreach ($faq as $f) {
$q = 'faq'.$i;
$a = 'faq'.$i.'_answer';
echo $f[$a];
echo $f[$a];
$i++;
}
I am attempting to use a for loop or for each loop to push the values from a get query to another variable. May I have some help with this approach?
Ok here is where I am:
for ($i = 0 ; i < $_GET['delete']; i++) {
$_jid [] = $_GET['delete'];
}
You don't actually need a loop here. If $_jid already is an array containing some values, consider just merging it with $_GET['delete'].
if (is_array($_jid)) {
$_jid = array_merge($_jid, $_GET['delete']);
}
If $_jid is not an array and doesn't exist except as a container for $_GET['delete'] you do can just assign the array. There is no need to loop at all.
$_jid = $_GET['delete'];
Of course in that case, you don't even need to copy it. You can just use $_GET['delete'] directly, in any context you planned to read from $_jid.
Update:
If the contents of $_GET['delete'] are originally 923,936, that is not an array to begin with, but rather a string. If you want an array out of it, you need to explode() it on assignment:
$_jid = explode(',', $_GET['delete']);
But if you intend to implode() it in the end anyway, there's obviously no need to do that. You already have exactly the comma-delimited string you want.
As you can see if you do a var_dump($_GET), the variable $_GET is a hashmap.
You can easily use a foreach loop to look through every member of it :
foreach($_GET as $get) // $get will successively take the values of $_GET
{
echo $get."<br />\n"; // We print these values
}
The code above will print the value of the $_GET members (you can try it with a blank page and dull $_GET values, as "http://yoursite.usa/?get1=stuff&get2=morestuff")
Instead of a echo, you can put the $_GET values into an array (or other variables) :
$array = array(); // Creating an empty array
$i = 0; // Counter
foreach($_GET as $get)
{
$array[$i] = $get; // Each $_GET value is store in a $array slot
$i++;
}
In PHP, foreach is quite useful and very easy to use.
However, you can't use a for for $_GET because it's a hashmap, not an array (in fact, you can, but it's much more complicated).
Hope I helped
If you have any array $p that you populated in a loop like so:
$p[] = array( "id"=>$id, "Name"=>$name);
What's the fastest way to search for John in the Name key, and if found, return the $p index? Is there a way other than looping through $p?
I have up to 5000 names to find in $p, and $p can also potentially contain 5000 rows. Currently I loop through $p looking for each name, and if found, parse it (and add it to another array), splice the row out of $p, and break 1, ready to start searching for the next of the 5000 names.
I was wondering if there if a faster way to get the index rather than looping through $p eg an isset type way?
Thanks for taking a look guys.
Okay so as I see this problem, you have unique ids, but the names may not be unique.
You could initialize the array as:
array($id=>$name);
And your searches can be like:
array_search($name,$arr);
This will work very well as native method of finding a needle in a haystack will have a better implementation than your own implementation.
e.g.
$id = 2;
$name= 'Sunny';
$arr = array($id=>$name);
echo array_search($name,$arr);
Echoes 2
The major advantage in this method would be code readability.
If you know that you are going to need to perform many of these types of search within the same request then you can create an index array from them. This will loop through the array once per index you need to create.
$piName = array();
foreach ($p as $k=>$v)
{
$piName[$v['Name']] = $k;
}
If you only need to perform one or two searches per page then consider moving the array into an external database, and creating the index there.
$index = 0;
$search_for = 'John';
$result = array_reduce($p, function($r, $v) use (&$index, $search_for) {
if($v['Name'] == $search_for) {
$r[] = $index;
}
++$index;
return $r;
});
$result will contain all the indices of elements in $p where the element with key Name had the value John. (This of course only works for an array that is indexed numerically beginning with 0 and has no “holes” in the index.)
Edit: Possibly even easier to just use array_filter, but that will not return the indices only, but all array element where Name equals John – but indices will be preserved:
$result2 = array_filter($p, function($elem) {
return $elem["Name"] == "John" ? true : false;
});
var_dump($result2);
What suits your needs better, resp. which one is maybe faster, is for you to figure out.