I have the following code snippet.
$items['A'] = "Test";
$items['B'] = "Test";
$items['C'] = "Test";
$items['D'] = "Test";
$index = 0;
foreach($items as $key => $value)
{
echo "$index is a $key containing $value\n";
$index++;
}
Expected output:
0 is a A containing Test
1 is a B containing Test
2 is a C containing Test
3 is a D containing Test
Is there a way to leave out the $index variable?
Your $index variable there kind of misleading. That number isn't the index, your "A", "B", "C", "D" keys are. You can still access the data through the numbered index $index[1], but that's really not the point. If you really want to keep the numbered index, I'd almost restructure the data:
$items[] = array("A", "Test");
$items[] = array("B", "Test");
$items[] = array("C", "Test");
$items[] = array("D", "Test");
foreach($items as $key => $value) {
echo $key.' is a '.$value[0].' containing '.$value[1];
}
You can do this:
$items[A] = "Test";
$items[B] = "Test";
$items[C] = "Test";
$items[D] = "Test";
for($i=0;$i<count($items);$i++)
{
list($key,$value) = each($items[$i]);
echo "$i $key contains $value";
}
I haven't done that before, but in theory it should work.
Be careful how you're defining your keys there. While your example works, it might not always:
$myArr = array();
$myArr[A] = "a"; // "A" is assumed.
echo $myArr['A']; // "a" - this is expected.
define ('A', 'aye');
$myArr2 = array();
$myArr2[A] = "a"; // A is a constant
echo $myArr['A']; // error, no key.
print_r($myArr);
// Array
// (
// [aye] => a
// )
Related
I have an array which is defined as $array[colname]. For each value in $array[colname], I would like to append a piece of text to the end. The value already inside is string and I will append a string as well.
There are at least two possibilities
Edit the array in place:
foreach($a as &$v) {
$v .= 'APPENDED';
}
or
foreach($a as $k => $v) {
$a[$k] = $v . 'APPENDED';
}
Create a new array by mapping the old values to their new values:
$appended_array = array_map(function($v) { return $v . 'APPENDED'; }, $a);
Like this? You can easily iterate throug arrays
Here are the docs: http://php.net/manual/en/control-structures.foreach.php
Tip: Next time you should search on google and php.net because most default stuff are documented and in your question you used the right keywords that you needed to find it yourself
<?php
//Could write this shorter
$array = array();
$array['column1'] = 'value1';
$array['column2'] = 'value2';
//This is the short way
//http://php.net/manual/en/language.types.array.php
$array = array('column1' => 'value1', 'column2' => 'value2');
//Iterate throug every value in $array (That is every $array[colname])
//The & charachter before the $value means pass-by-reference you should do some research to understand this ;)
//foreach($array['colname'] as &$value) { for a single column with multiple values in it
foreach($array as &$value) {
// .= is the same as $value = $value . 'append'
// This way we append the text
$value .= 'append';
}
//Outputs all values in $array
print_r($array());
?>
You can use array_walk like below:
<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
function test_alter(&$item1, $key, $string)
{
$item1 = "$item1 : $string";
}
array_walk($fruits, 'test_alter', 'fruit');
echo "... and after:\n";
array_walk($fruits, 'test_print');
?>
Output will be like this:
... and after:
d. lemon:fruit
a. orange:fruit
b. banana:fruit
c. apple:fruit
for more info:http://php.net/manual/en/function.array-walk.php
Here's the tested solution provided array matches to your stucture
<?php
$array = array();
$array['c1'] = array(1=>'data1', 2=>'data2', 3=>'data3', 4=>'data4');
$array['c2'] = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
echo '<pre> Original Array : <br/>';
print_r($array);
foreach($array as $key=>$value)
{
foreach($value as $sub_key=>$sub_value)
{
$textToAppend = '_AppendedMe';
echo '<br/> brfore : '.$value[$sub_key];
$sub_value .= $textToAppend;
$array[$key][$sub_key]=$sub_value;
echo '<br/> after : '.$value[$sub_key];
}
}
echo '<br/> Array after : ';
print_r($array);
echo '</pre>';
?>
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';
}
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 $$arrayVarName[$key],PHP_EOL;
}
echo PHP_EOL;
}
Will work as long as all the arrays defined in $status exist, and you have matching keys in $n, $p and $a
Updated to allow for $status
You could use next() in a while loop.
Example: http://ideone.com/NTIuJ
EDIT:
Unlike other answers this method works whether the keys match or not, even is the arrays are lists, not dictionaries.
If I understand your goal correctly, I'd start by putting each array p/n/... in an array:
$status = array();
$status['n'] = array();
$status['n']['minutes'] = a;
$status['n']['dollars'] = b;
$status['n']['units'] = c;
$status['p'] = array();
$status['p']['minutes'] = a;
$status['p']['dollars'] = b;
$status['p']['units'] = c;
Then you can read each array with:
foreach($status as $name => $values){
echo 'Array '.$name.': <br />';
echo 'Minutes: '.$values['minutes'].'<br />';
echo 'Dollars: '.$values['dollars'].'<br />';
echo 'Units: '.$values['units'].'<br />';
}
For more information, try googling Multidimensional Arrays.
how take string from array define as new array,
how to code in php
$column = array("id","name","value");
let say found 3 row from mysql
want result to be like this
$id[0] = "1";
$id[1] = "6";
$id[2] = "10";
$name[0] = "a";
$name[1] = "b";
$name[2] = "c";
$value[0] = "bat";
$value[1] = "rat";
$value[2] = "cat";
I want to take string from $column array define as new array.
how to code it?
or if my question is stupid , my please to have suggestion.
thank you.
Answer I made on your previous question:
$result = mysql_query($sql);
$num = mysql_num_rows($result);
$i = 0;
if ($num > 0) {
while ($row = mysql_fetch_assoc($result)) {
foreach($row as $column_name => $column_value) {
$temp_array[$column_name][$i] = $column_value;
}
$i++;
}
foreach ($temp_array as $name => $answer) {
$$name = $answer;
}
}
I can't see why you'd want to model your data like this, you're asking for a world of hurt in terms of debugging. There are "variable variables" you could use to define this, or build global variables dynamically using $GLOBALS:
$somevar = "hello"
$$somevar[0] = "first index"; // creates $hello[0]
$GLOBALS[$somevar][0] = "first index"; // creates $hello[0] in global scope
try
$array = array();
foreach ($results as $r){
foreach ($column as $col ){
$array[$col][] = $r[$col];
}
}
extract ($array);
or you can simply do this
$id = array();
$name = array();
$value = array();
foreach ( $results as $r ){
$id[] = $r['id']; // or $r[0];
$name[] = $r['name'];
$value[] = $r['value'];
}
Hope this is what you asked
This is pretty dangerous, as it may overwrite variables you consider safe in your code. What you're looking for is extract:
$result = array();
while ($row = mysql_fetch_array($result))
foreach ($column as $i => $c)
$result[$c][] = $row[$i];
extract($result);
So, if $result was array( 'a' => array(1,2), 'b' => array(3,4)), the last line defines variables $a = array(1,2) and $b = array(3,4).
You cannot use variable variables right on for this, and you shouldn't anyway. But this is how you could do it:
foreach (mysql_fetch_something() as $row) {
foreach ($row as $key=>$value) {
$results[$key][] = $value;
}
}
extract($results);
Ideally you would skip the extract, and use $results['id'][1] etc. But if you only extract() the nested array in subfunctions, then the local variable scope pollution is acceptable.
There is no need for arrays or using $_GLOBALS, i believe the best way to create variables named based on another variable value is using curly brackets:
$variable_name="value";
${$variable_name}="3";
echo $value;
//Outputs 3
If you are more specific on what is the array you receive i can give a more complete solution, although i must warn you that i have never had to use such method and it's probably a sign of a bad idea.
If you want to learn more about this, here is a useful link:
http://www.reddit.com/r/programming/comments/dst56/today_i_learned_about_php_variable_variables/
I want to add data to an array dynamically. How can I do that? Example
$arr1 = [
'aaa',
'bbb',
'ccc',
];
// How can I now add another value?
$arr2 = [
'A' => 'aaa',
'B' => 'bbb',
'C' => 'ccc',
];
// How can I now add a D?
There are quite a few ways to work with dynamic arrays in PHP.
Initialise an array:
$array = array();
Add to an array:
$array[] = "item"; // for your $arr1
$array[$key] = "item"; // for your $arr2
array_push($array, "item", "another item");
Remove from an array:
$item = array_pop($array);
$item = array_shift($array);
unset($array[$key]);
There are plenty more ways, these are just some examples.
$array[] = 'Hi';
pushes on top of the array.
$array['Hi'] = 'FooBar';
sets a specific index.
Let's say you have defined an empty array:
$myArr = array();
If you want to simply add an element, e.g. 'New Element to Array', write
$myArr[] = 'New Element to Array';
if you are calling the data from the database, below code will work fine
$sql = "SELECT $element FROM $table";
$query = mysql_query($sql);
if(mysql_num_rows($query) > 0)//if it finds any row
{
while($result = mysql_fetch_object($query))
{
//adding data to the array
$myArr[] = $result->$element;
}
}
You should use method array_push to add value or array to array exists
$stack = array("orange", "banana");
array_push($stack, "apple", "raspberry");
print_r($stack);
/** GENERATED OUTPUT
Array
(
[0] => orange
[1] => banana
[2] => apple
[3] => raspberry
)
*/
Like this?:
$array[] = 'newItem';
In additon to directly accessing the array, there is also
array_push — Push one or more elements onto the end of array
$dynamicarray = array();
for($i=0;$i<10;$i++)
{
$dynamicarray[$i]=$i;
}
Adding array elements dynamically to an Array And adding new element
to an Array
$samplearr=array();
$count = 0;
foreach ($rslt as $row) {
$arr['feeds'][$count]['feed_id'] = $row->feed_id;
$arr['feeds'][$count]['feed_title'] = $row->feed_title;
$arr['feeds'][$count]['feed_url'] = $row->feed_url;
$arr['feeds'][$count]['cat_name'] = $this->get_catlist_details($row->feed_id);
foreach ($newelt as $cat) {
array_push($samplearr, $cat);
}
++$count;
}
$arr['categories'] = array_unique($samplearr); //,SORT_STRING
$response = array("status"=>"success","response"=>"Categories exists","result"=>$arr);
just for fun...
$array_a = array('0'=>'foo', '1'=>'bar');
$array_b = array('foo'=>'0', 'bar'=>'1');
$array_c = array_merge($array_a,$array_b);
$i = 0; $j = 0;
foreach ($array_c as $key => $value) {
if (is_numeric($key)) {$array_d[$i] = $value; $i++;}
if (is_numeric($value)) {$array_e[$j] = $key; $j++;}
}
print_r($array_d);
print_r($array_e);
Fastest way I think
$newArray = array();
for($count == 0;$row = mysql_fetch_assoc($getResults);$count++)
{
foreach($row as $key => $value)
{
$newArray[$count]{$key} = $row[$key];
}
}