How to find the foreach index?

PhpLoopsForeach

Php Problem Overview


Is it possible to find the foreach index?

in a for loop as follows:

for ($i = 0; $i < 10; ++$i) {
   echo $i . ' ';
}

$i will give you the index.

Do I have to use the for loop or is there some way to get the index in the foreach loop?

Php Solutions


Solution 1 - Php

foreach($array as $key=>$value) {
    // do stuff
}

$key is the index of each $array element

Solution 2 - Php

You can put a hack in your foreach, such as a field incremented on each run-through, which is exactly what the for loop gives you in a numerically-indexed array. Such a field would be a pseudo-index that needs manual management (increments, etc).

A foreach will give you your index in the form of your $key value, so such a hack shouldn't be necessary.

e.g., in a foreach

$index = 0;
foreach($data as $key=>$val) {
    // Use $key as an index, or...
 
    // ... manage the index this way..
    echo "Index is $index\n";
    $index++;
}

Solution 3 - Php

It should be noted that you can call key() on any array to find the current key its on. As you can guess current() will return the current value and next() will move the array's pointer to the next element.

Solution 4 - Php

Owen has a good answer. If you want just the key, and you are working with an array this might also be useful.

foreach(array_keys($array) as $key) {
//  do stuff
}

Solution 5 - Php

You can create $i outside the loop and do $i++ at the bottom of the loop.

Solution 6 - Php

These two loops are equivalent (bar the safety railings of course):

for ($i=0; $i<count($things); $i++) { ... }

foreach ($things as $i=>$thing) { ... }

eg

for ($i=0; $i<count($things); $i++) {
    echo "Thing ".$i." is ".$things[$i];
}

foreach ($things as $i=>$thing) {
    echo "Thing ".$i." is ".$thing;
}

Solution 7 - Php

I think best option is like same:

foreach ($lists as $key=>$value) {
    echo $key+1;
}

it is easy and normally

Solution 8 - Php

PHP arrays have internal pointers, so try this:

foreach($array as $key => $value){
   $index = current($array);
}

Works okay for me (only very preliminarily tested though).

Solution 9 - Php

Jonathan is correct. PHP arrays act as a map table mapping keys to values. in some cases you can get an index if your array is defined, such as

$var = array(2,5);

for ($i = 0; $i < count($var); $i++) {
	echo $var[$i]."\n";
}

your output will be

2
5

in which case each element in the array has a knowable index, but if you then do something like the following

$var = array_push($var,10);

for ($i = 0; $i < count($var); $i++) {
	echo $var[$i]."\n";
}

you get no output. This happens because arrays in PHP are not linear structures like they are in most languages. They are more like hash tables that may or may not have keys for all stored values. Hence foreach doesn't use indexes to crawl over them because they only have an index if the array is defined. If you need to have an index, make sure your arrays are fully defined before crawling over them, and use a for loop.

Solution 10 - Php

I use ++$key instead of $key++ to start from 1. Normally it starts from 0.

@foreach ($quiz->questions as $key => $question)
 <h2> Question: {{++$key}}</h2>
 <p>{{$question->question}}</p>
@endforeach

Output:

Question: 1
......
Question:2
.....
.
.
.

Solution 11 - Php

I solved this way, when I had to use the foreach index and value in the same context:

$array = array('a', 'b', 'c');
foreach ($array as $letter=>$index) {

  echo $letter; //Here $letter content is the actual index
  echo $array[$letter]; // echoes the array value

}//foreach

Solution 12 - Php

I normally do this when working with associative arrays:

foreach ($assoc_array as $key => $value) {
 //do something
}

This will work fine with non-associative arrays too. $key will be the index value. If you prefer, you can do this too:

foreach ($array as $indx => $value) {
  //do something
}

Solution 13 - Php

foreach(array_keys($array) as $key) {
//  do stuff
}

Solution 14 - Php

I would like to add this, I used this in laravel to just index my table:

  • With $loop->index
  • I also preincrement it with ++$loop to start at 1

My Code:

@foreach($resultsPerCountry->first()->studies as $result)
  <tr>
    <td>{{ ++$loop->index}}</td>                                    
  </tr>
@endforeach

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Questionuser18334View Question on Stackoverflow
Solution 1 - PhpOwenView Answer on Stackoverflow
Solution 2 - PhpConroyPView Answer on Stackoverflow
Solution 3 - PhpBailey ParkerView Answer on Stackoverflow
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Solution 5 - PhpÓlafur WaageView Answer on Stackoverflow
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