I have several arrays: $n, $p, $a
Each array is the same:
$n = array()
$n['minutes'] = a;
$n['dollars'] = b;
$n['units'] = c;
$p = array()
$p['minutes'] = x;
$p['dollars'] = y;
$p['units'] = z;
etc...
I also have a simple array like this:
$status = array('n', 'p', 'a');
Is it possible for me to use the $status array to loop through the other arrays?
Something like:
foreach($status as $key => $value) {
//display the amounts amount here
};
So I would end up with:
a
x
b
y
c
z
Or, do I need to somehow merge all the arrays into one?
Use:
$arrayData=array('minutes','dollars','units');
foreach($arrayData as $data) {
foreach($status as $value) {
var_dump(${$value}[$data]);
}
}
foreach($n as $key => $value) {
foreach($status as $arrayVarName) (
echo $$arrayVarName[$key],PHP_EOL;
}
echo PHP_EOL;
}
Will work as long as all the arrays defined in $status exist, and you have matching keys in $n, $p and $a
Updated to allow for $status
You could use next() in a while loop.
Example: http://ideone.com/NTIuJ
EDIT:
Unlike other answers this method works whether the keys match or not, even is the arrays are lists, not dictionaries.
If I understand your goal correctly, I'd start by putting each array p/n/... in an array:
$status = array();
$status['n'] = array();
$status['n']['minutes'] = a;
$status['n']['dollars'] = b;
$status['n']['units'] = c;
$status['p'] = array();
$status['p']['minutes'] = a;
$status['p']['dollars'] = b;
$status['p']['units'] = c;
Then you can read each array with:
foreach($status as $name => $values){
echo 'Array '.$name.': <br />';
echo 'Minutes: '.$values['minutes'].'<br />';
echo 'Dollars: '.$values['dollars'].'<br />';
echo 'Units: '.$values['units'].'<br />';
}
For more information, try googling Multidimensional Arrays.
Related
I tried to use a foreach loop on a multi-dimensional array, and found out that it didn't exactly worked out the way that I expected. Is there a foreach loop for multi-dimensional arrays, or another way to do this?
$array[0][0] = "a";
$array[0][1] = "b";
$array[0][2] = "c";
foreach($array as $a) {
echo $a."<br>";
}
Result:
Nothing
Needed Result:
a
b
c
You could also try this:
foreach($array[0] as $key => $value){
echo $value . "<br>":
}
$array in this code you're accessing the key of 0,0,0 so it will not print it.
$array[0] in this code you're both accessing key 0,1,2 and the values a,b and c
You need two loops. One to loop the first array, and one to loop the inner one.
foreach($array as $key) {
foreach($key as $val) {
echo $val;
}
}
Try nesting another foreach...
$array[0][0] = "a";
$array[0][1] = "b";
$array[0][2] = "c";
foreach($array as $a) {
foreach($a as $val){
echo $val."<br>";
}
}
It is because $a is still an array. If you use print_r() you will see this:
foreach($array as $a) {
print_r($a);
}
Result:
Array
(
[0] => a
[1] => b
[2] => c
)
To combat the nested array you have to run a second foreach() loop to get the values:
foreach($array as $a) {
foreach($a as $value){ // loop through second array
echo $value . "</ br>";
}
}
well since no one else has mentioned it:
<?php
$array[0][0] = "a";
$array[0][1] = "b";
$array[0][2] = "c";
echo implode('<br>',$array[0]);
http://codepad.viper-7.com/SC9PLI
I write a code for sync two array and know which was must delete and which was add to new array.
<?php
$currentArray = array('ali', 'hasan', 'husein'); //base array read from database
$saveArray = array('husein', 'Hasan', 'taghi'); //requested item for save/delete in database
$deleteArray = array();
$addArray = array();
$currentArray = array_map('strtolower', $currentArray);
$saveArray = array_map('strtolower', $saveArray);
foreach ($currentArray as $a) {
if (!in_array($a, $saveArray))
$deleteArray[] = $a;
}
foreach ($saveArray as $a) {
if (!in_array($a, $currentArray))
$addArray[] = $a;
}
echo 'must be deleted:';
var_dump($deleteArray);
echo 'must be added:';
var_dump($addArray);
?>
Output:
must be deleted:
array
0 => string 'ali' (length=3)
must be added:
array
0 => string 'taghi' (length=5)
Now, Do you thinks is it better, faster and simpler code for this action?
You can use array_udiff() for this, using strcasecmp() as the callback function.
$currentArray = array('ali', 'hasan', 'husein');
$saveArray = array('husein', 'Hasan', 'taghi');
$deleteArray = array_udiff($currentArray, $saveArray, 'strcasecmp');
$addArray = array_udiff($saveArray, $currentArray, 'strcasecmp');
See demo
The values must be the same.
$currentArray = array_map('strtolower', $currentArray);
$saveArray = array_map('strtolower', $saveArray);
And basically use use Array diff.
$deleteArray = array_diff($currentArray, $saveArray);
$addArray = array_diff($saveArray, $currentArray);
This question already has answers here:
How does PHP 'foreach' actually work?
(7 answers)
Closed 8 years ago.
Consider the code below:
<?php
$arr = array();
$arr['b'] = 'book';
foreach($arr as $key=>$val) {
print "key=>$key\n";
if(!isset($arr['a']))
$arr['a'] = 'apple';
}
?>
It is not displaying 'a'. How foreach works with hash-table(array), to traverse each element. If lists are implement why can't I add more at run time ?
Please don't tell me that I could do this task with numeric based index with help of counting.
Foreach copies structure of array before looping(read more), so you cannot change structure of array and wait for new elements inside loop. You could use while instead of foreach.
$arr = array();
$arr['b'] = 'book';
reset($arr);
while ($val = current($arr))
{
print "key=".key($arr).PHP_EOL;
if (!isset($arr['a']))
$arr['a'] = 'apple';
next($arr);
}
Or use ArrayIterator with foreach, because ArrayIterator is not an array.
$arr = array();
$arr['b'] = 'book';
$array_iterator = new ArrayIterator($arr);
foreach($array_iterator as $key=>$val) {
print "key=>$key\n";
if(!isset($array_iterator['a']))
$array_iterator['a'] = 'apple';
}
I think you need to store array element continue sly
Try
<?php
$arr = array();
$arr['b'] = 'book';
foreach($arr as $key=>$val) {
print "key=>$key\n";
if(!isset($arr['a']))
$arr['a'][] = 'apple';
}
print_r($arr);
?>
In order to be able to directly modify array elements within the loop precede $value with &. In that case the value will be assigned by reference.
http://cz2.php.net/manual/en/control-structures.foreach.php
Try this:
You will get values.
<?php
$arr = array();
$arr['b'] = 'book';
foreach($arr as $key=>$val) {
print "key=>$key\n";
if(!isset($arr['a']))
$arr['a'] = 'apple';
}
echo '<pre>';
print_r($arr);
?>
Output:
key=>b
<pre>Array
(
[b] => book
[a] => apple
)
If you want to check key exist or not in array use array_key_exists function
Eg:
<?php
$arr = array();
$arr['b'] = 'book';
print_r($arr); // prints Array ( [b] => book )
if(!array_key_exists("a",$arr))
$arr['a'] = 'apple';
print_r($arr); // prints Array ( [b] => book [a] => apple )
?>
If you want to use isset condition try like this:
$arr = array();
$arr['b'] = 'book';
$flag = 0;
foreach($arr as $key=>$val) {
print "key=>$key\n";
if(!isset($arr["a"]))
{
$flag = 1;
}
}
if(flag)
{
$arr['a'] = 'apple';
}
print_r($arr);
How about using for and realtime array_keys()?
<?php
$arr = array();
$arr['b'] = 'book';
for ($x=0;$x<count($arr); $x++) {
$keys = array_keys($arr);
$key = $keys[$x];
print "key=>$key\n";
if(!isset($arr['a']))
$arr['a'] = 'apple';
}
For example:
$arr = array(3,5,2,5,3,9);
I want to show only common elements i.e 3,5 as output.
Here's my attempt:
<?php
$arr = array(3,5,2,5,3,9);
$temp_array = array();
foreach($arr as $val)
{
if(isset($temp_array[$val]))
{
$temp_array[$val] = $val;
}else{
$temp_array[$val] = 0;
}
}
foreach($temp_array as $val2)
{
if($val2 > 0)
{
echo $val2 . ', ';
}
}
?>
--
Output --
3, 5,
Try the following:
$arr = array(3,5,2,5,3,9);
foreach($arr as $key => $val){
//remove the item from the array in order
//to prevent printing duplicates twice
unset($arr[$key]);
//now if another copy of this key still exists in the array
//print it since it's a dup
if (in_array($val,$arr)){
echo $val . " ";
}
}
Output:
3 5
Addition:
I guess that the reason you were asked to implement it yourself (without using built-in functions) was to avoid answers like:
$unique = array_unique($arr);
$dupes = array_diff_key( $arr, $unique );
$arrnew = array();
for($i=0;$i<count($arr);$i++)
{
for($j=$i+1;$j<count($arr);$j++)
{
if($arr[$i]==$arr[$j])
{
$arrnew[]=$arr[$j];
}
}
}
Let's say I have this:
$array = array("john" => "doe", "foe" => "bar", "oh" => "yeah");
foreach($array as $i=>$k)
{
echo $i.'-'.$k.',';
}
echoes "john-doe,foe-bar,oh-yeah,"
How do I get rid of the last comma?
Alternatively you can use the rtrim function as:
$result = '';
foreach($array as $i=>$k) {
$result .= $i.'-'.$k.',';
}
$result = rtrim($result,',');
echo $result;
I dislike all previous recipes.
Php is not C and has higher-level ways to deal with this particular problem.
I will begin from the point where you have an array like this:
$array = array('john-doe', 'foe-bar', 'oh-yeah');
You can build such an array from the initial one using a loop or array_map() function. Note that I'm using single-quoted strings. This is a micro-optimization if you don't have variable names that need to be substituted.
Now you need to generate a CSV string from this array, it can be done like this:
echo implode(',', $array);
One method is by using substr
$array = array("john" => "doe", "foe" => "bar", "oh" => "yeah");
$output = "";
foreach($array as $i=>$k)
{
$output .= $i.'-'.$k.',';
}
$output = substr($output, 0, -1);
echo $output;
Another method would be using implode
$array = array("john" => "doe", "foe" => "bar", "oh" => "yeah");
$output = array();
foreach($array as $i=>$k)
{
$output[] = $i.'-'.$k;
}
echo implode(',', $output);
I don't like this idea of using substr at all, since it's the style of bad programming. The idea is to concatenate all elements and to separate them by special "separating" phrases. The idea to call the substring for that is like to use a laser to shoot the birds.
In the project I am currently dealing with, we try to get rid of bad habits in coding. And this sample is considered one of them. We force programmers to write this code like this:
$first = true;
$result = "";
foreach ($array as $i => $k) {
if (!$first) $result .= ",";
$first = false;
$result .= $i.'-'.$k;
}
echo $result;
The purpose of this code is much clearer, than the one that uses substr. Or you can simply use implode function (our project is in Java, so we had to design our own function for concatenating strings that way). You should use substr function only when you have a real need for that. Here this should be avoided, since it's a sign of bad programming style.
I always use this method:
$result = '';
foreach($array as $i=>$k) {
if(strlen($result) > 0) {
$result .= ","
}
$result .= $i.'-'.$k;
}
echo $result;
try this code after foreach condition then echo $result1
$result1=substr($i, 0, -1);
Assuming the array is an index, this is working for me. I loop $i and test $i against the $key. When the key ends, the commas do not print. Notice the IF has two values to make sure the first value does not have a comma at the very beginning.
foreach($array as $key => $value)
{
$w = $key;
//echo "<br>w: ".$w."<br>";// test text
//echo "x: ".$x."<br>";// test text
if($w == $x && $w != 0 )
{
echo ", ";
}
echo $value;
$x++;
}
this would do:
rtrim ($string, ',')
see this example you can easily understand
$name = ["sumon","karim","akash"];
foreach($name as $key =>$value){
echo $value;
if($key<count($name){
echo ",";
}
}
I have removed comma from last value of aray by using last key of array. Hope this will give you idea.
$last_key = end(array_keys($myArray));
foreach ($myArray as $key => $value ) {
$product_cateogry_details="SELECT * FROM `product_cateogry` WHERE `admin_id`='$admin_id' AND `id` = '$value'";
$product_cateogry_details_query=mysqli_query($con,$product_cateogry_details);
$detail=mysqli_fetch_array($product_cateogry_details_query);
if ($last_key == $key) {
echo $detail['product_cateogry'];
}else{
echo $detail['product_cateogry']." , ";
}
}
$foods = [
'vegetables' => 'brinjal',
'fruits' => 'orange',
'drinks' => 'water'
];
$separateKeys = array_keys($foods);
$countedKeys = count($separateKeys);
for ($i = 0; $i < $countedKeys; $i++) {
if ($i == $countedKeys - 1) {
echo $foods[$separateKeys[$i]] . "";
} else {
echo $foods[$separateKeys[$i]] . ", \n";
}
}
Here $foods is my sample associative array.
I separated the keys of the array to count the keys.
Then by a for loop, I have printed the comma if it is not the last element and removed the comma if it is the last element by $countedKeys-1.