range

(PHP 4, PHP 5, PHP 7, PHP 8)

range — Erstellt ein Array mit einem Bereich von Elementen

Beschreibung

Erstellt ein Array mit einem Bereich von Elementen.

Wenn sowohl start als auch end vom Typ string sind und step vom Typ int ist, ist das erzeugte Array eine Folge von Bytes. Andernfalls ist das erzeugte Array eine Folge von Zahlen.

Wenn der start kleiner ist als end, ist die Folge aufsteigend, andernfalls ist sie absteigend.

Parameter-Liste

start

Der erste Wert der Folge.

end

Der letzte mögliche Wert der Folge.

step

step gibt an, wie weit die einzelnen Werte der erzeugten Folge auseinander liegen.

step kann für absteigende Folgen negativ sein.

Wenn step ein float ohne Nachkommastelle ist, wird er als int interpretiert.

Rückgabewerte

Gibt eine Folge von Elementen als Array zurück, beginnend mit start und endend mit end, wobei die einzelnen Werte der Folge einen Abstand von step voneinander haben.

Das letzte Element des zurückgegebenen Arrays ist in Abhängigkeit vom Wert von step entweder end oder das vorherige Element der Folge.

Wenn sowohl start als auch end vom Typ string sind und step vom Typ int ist, besteht das erzeugte Array aus einer Folge von Bytes, in der Regel lateinische ASCII-Zeichen.

Wenn mindestens einer der Parameter start, end oder step vom Typ float ist, ist das erzeugte Array eine Folge vom Typ float.

Andernfalls ist das erzeugte Array eine Folge vom Typ int.

Fehler/Exceptions

Wenn step 0 ist, wird ein ValueError geworfen.
Wenn start, end oder step nicht is_finite() ist, wird ein ValueError geworfen.
Wenn step negativ ist, aber der erzeugte Bereich größer wird (d. h. $start <= $end), wird ein ValueError geworfen.
Wenn start oder end die leere Zeichenkette '' ist, wird ein E_WARNING ausgegeben und die leere Zeichenkette wird als 0 interpretiert.
Wenn start oder end eine nicht-numerische Zeichenkette mit mehr als einem Byte ist, wird ein E_WARNING ausgegeben.
Wenn start oder end eine Zeichenkette ist, die implizit in den Typ int umgewandelt wird, weil der andere Begrenzungswert eine Zahl ist, wird ein E_WARNING ausgegeben.
Wenn step vom Typ float ist, und start und end nicht-numerische Zeichenketten sind, wird ein E_WARNING ausgegeben.

Changelog

Version	Beschreibung
8.3.0	Wenn sowohl `start` als auch `end` Zeichenketten sind, erzeugt range() nun immer ein Array aus Bytes. Zuvor wurde, wenn einer der Begrenzungswerte eine numerische Zeichenkette war, der andere Begrenzungswert implizit in int umgewandelt.
8.3.0	Wenn `start` oder `end` eine Zeichenkette ist, die implizit in int umgewandelt wird, weil der andere Begrenzungswert eine Zahl ist, wird nun ein `E_WARNING` ausgegeben.
8.3.0	Wenn `start` oder `end` eine nicht-numerische Zeichenkette mit mehr als einem Byte ist, wird nun ein `E_WARNING` ausgegeben.
8.3.0	Wenn `start` oder `end` die leere Zeichenkette ist, wird nun ein `E_WARNING` ausgegeben.
8.3.0	Wenn `step` ein float ohne Nachkommastelle ist, wird er als int interpretiert.
8.3.0	Wenn `step` negativ ist, wird nun ein ValueError ausgelöst, wenn ein aufsteigender Bereich erzeugt wird.
8.3.0	Wenn `step` nicht endlich ist, wird nun ein ValueError geworfen.
8.3.0	Wenn `start` oder `end` ein Array, Objekt oder eine Ressource ist, wird nun ein TypeError geworfen; zuvor wurden diese Werte implizit in int umgewandelt.

Beispiele

Beispiel #1 range()-Beispiele

<?php
echo implode(', ', range(0, 12)), PHP_EOL;

echo implode(', ', range(0, 100, 10)), PHP_EOL;

echo implode(', ', range('a', 'i')), PHP_EOL;

echo implode(', ', range('c', 'a')), PHP_EOL;

echo implode(', ', range('A', 'z')), PHP_EOL;
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100
a, b, c, d, e, f, g, h, i
c, b, a
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, [, \, ], ^, _, `, a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z

Siehe auch

shuffle() - Mischt die Elemente eines Arrays
array_fill() - Füllt ein Array mit Werten
foreach

add a note

User Contributed Notes 30 notes

down

131

Palz ¶

12 years ago


To create a range array like

Array
(
    [11] => 1
    [12] => 2
    [13] => 3
    [14] => 4
)

combine two range arrays using array_combine:

array_combine(range(11,14),range(1,4))

down

php at keith tyler dot com ¶

10 years ago


So with the introduction of single-character ranges to the range() function, the internal function tries to be "smart", and (I am inferring from behavior here) apparently checks the type of the incoming values. If one is numeric, including numeric string, then the other is treated as numeric; if it is a non-numeric string, it is treated as zero. 

But.

If you pass in a numeric string in such a way that is is forced to be recognized as type string and not type numeric, range() will function quite differently.

Compare:

<?php
echo implode("",range(9,"Q"));
// prints 9876543210

echo implode("",range("9 ","Q"));  //space after the 9
// prints 9:;<=>?@ABCDEFGHIJKLMNOPQ

echo implode("",range("q","9 "));
// prints qponmlkjihgfedcba`_^]\[ZYXWVUTSRQPONMLKJIHGFEDCBA@?>=<;:987654
?>

I wouldn't call this a bug, because IMO it is even more useful than the stock usage of the function.

down

ccb_bc at hotmail dot com ¶

5 years ago


<?php 
    function natural_prime_numbers(array $range, bool $print_info = false) : array {
        $start_time = time();
        $primes_numbers = array();
        $print = '';
        $count_range  = count($range);
        foreach($range as $number){
            $values_division_number = array();
            if($number === 0 || $number === 1 || !is_int($number)){ // eliminate 0, 1 and other no integer
                continue;
            }
            if($number != 2 && $number%2 === 0){ // eliminate 2 and pairs numbers
                continue;
            }
            for($i = 1; $i <= $number; $i++){
                $resultado_divisao = $number / $i;
                $values_division_number[$i] = $resultado_divisao;

                if($count_range <= 20){ // $count_range <= 20 (+ performance)
                    $print .= PHP_EOL;
                    $info = 'The number '.$number.' divided by the number '.$i.' is equal to: '.($number / $i);
                    $print .= $info;
                    if($i === $number){
                        $print .= PHP_EOL;
                    }
                }                    

                array_walk($values_division_number, function($value, $index) use (&$values_division_number, &$number){ // reference change values
                    // eliminate floats and others numbers not are equal 1 and own number
                    if(is_float($value) && $value != $number && $value > 1){
                        unset($values_division_number[$index]);
                    }
                });

                $values_division_number = array_values($values_division_number); // reindex array

                // here we want only array with 2 indexes with the values 1 and own number (rule to a natural prime number)
                if(count($values_division_number) === 2 && $values_division_number[0] === $number && $values_division_number[1] === 1){
                    $primes_numbers[$number] = $number;
                }

            }
        }
        return array(
            'length_prime_numbers' => count($primes_numbers),
            'prime_numbers' => array_values($primes_numbers),
            'print' => $print,
            'total_time_processing' => (time() - $start_time).' seconds.',
        );
    }
    var_dump(natural_prime_numbers(range(0, 11))); // here the range() function ;-)

    // Result:
    // array (size=3)
    //   'length_prime_numbers' => int 5
    //   'prime_numbers' => 
    //     array (size=5)
    //       0 => int 2
    //       1 => int 3
    //       2 => int 5
    //       3 => int 7
    //       4 => int 11
    //   'print' => string '
    // O número 2 dividido pelo número 1 é igual a: 2
    // O número 2 dividido pelo número 2 é igual a: 1

    // O número 3 dividido pelo número 1 é igual a: 3
    // O número 3 dividido pelo número 2 é igual a: 1.5
    // O número 3 dividido pelo número 3 é igual a: 1

    // O número 5 dividido pelo número 1 é igual a: 5
    // O número 5 dividido pelo número 2 é igual a: 2.5
    // O número 5 dividido pelo número 3 é igual a: 1.6666666666667
    // O número 5 dividido pelo número 4 é igual a: 1.25
    // O número 5 dividido pelo '...

    // **************************** //
    //
    // * Remember that the function is recursive, that is: a range of 5000 takes more than 1 minute on a processor Intel® Core™ i5-8250U (3.40 GHz).
    //
    // **************************** //
?>

down

gtisza at gmail dot com ¶

11 years ago


You might expect range($n, $n-1) to be an empty array (as in e.g. Python) but actually PHP will assume a step of -1 if start is larger than end.

down

Alien426 ¶

9 years ago


The function will generate an array of integers even if your numerical parameters are enclosed in quotes.
<?php
var_dump( range('1', '2') ); // outputs  array(2) { [0]=> int(1) [1]=> int(2) }
?>

An easy way to get an array of strings is to map strval() to the range:
<?php
var_dump( array_map('strval', range('1', '2')) ); // outputs  array(2) { [0]=> string(1) "1" [1]=> string(1) "2" }
?>

down

luca.favorido ATgmailDOT com ¶

8 years ago


The function "range" is very useful to get an array of characters as range('C','R') does.

At work, I had to extend the function range($a,$b) to work in this special case: with two uppercase strings $a and $b, it should return all the possible strings between $a and $b.
This could be used for example to get the excel column indexes.
e.g. <?php range('A','AD') ==> array('A','B','C',...,'Z','AA','AB','AC','AD') ?>

So I wrote the function getrange($min,$max) that exactly does this.

<?php

function getcolumnrange($min,$max){
      $pointer=strtoupper($min);
      $output=array();
      while(positionalcomparison($pointer,strtoupper($max))<=0){
         array_push($output,$pointer);
         $pointer++;
      }
      return $output;
}

function positionalcomparison($a,$b){
   $a1=stringtointvalue($a); $b1=stringtointvalue($b);
   if($a1>$b1)return 1;
   else if($a1<$b1)return -1;
   else return 0;
}

/*
* e.g. A=1 - B=2 - Z=26 - AA=27 - CZ=104 - DA=105 - ZZ=702 - AAA=703
*/
function stringtointvalue($str){
   $amount=0;
   $strarra=array_reverse(str_split($str));

   for($i=0;$i<strlen($str);$i++){
      $amount+=(ord($strarra[$i])-64)*pow(26,$i);
   }
   return $amount;
}
?>

down

ThinkMedical at Gmail dot com ¶

16 years ago


foreach(range()) whilst efficiant in other languages, such as python, it is not (compared to a for) in php*.

php is a C-inspired language and thus for is entirely in-keeping with the lanuage aethetic to use it

<?php
//efficiant
for($i = $start; $i < $end; $i+=$step) 
{
        //do something with array 
}

//inefficiant
foreach(range($start, $end, $step) as $i)
{
        //do something with array 
}
?>

That the officiant documentation doesnt mention the for loop is strange.

Note however, that in PHP5 foreach is faster than for when iterating without incrementing a variable.

* My tests using microtime and 100 000 iterations consistently (~10 times) show that for is 4x faster than foreach(range()).

down

jazzduck AT gmail DOT com ¶

10 years ago


Despite the line above that says that the $step value should be "given as a positive number," the range() function will in fact correctly handle reversed (decrementing) ranges. For example:

<?php print_r( range( 24, 20 ) ); ?>
Array
(
    [0] => 24
    [1] => 23
    [2] => 22
    [3] => 21
    [4] => 20
)

<?php print_r( range( 20, 11, -3 ) ); ?>
Array
(
    [0] => 20
    [1] => 17
    [2] => 14
    [3] => 11
)

It will actually ignore the sign of the $step argument, and determine whether to increment or decrement based purely on whether $start > $end or $end > $start. For example:

<?php print_r( range( 20, 11, 3 ) ); ?>
Array
(
    [0] => 20
    [1] => 17
    [2] => 14
    [3] => 11
)

<?php print_r( range( 11, 20, -3 ) ); ?>
Array
(
    [0] => 11
    [1] => 14
    [2] => 17
    [3] => 20
)

down

ktamas77 at gmail dot com ¶

12 years ago


if you need zero padding, string prefixes or any other masks, then a simple combination of array_map, inline functions and sprintf is your friend.

<?php

$a = array_map(function($n) { return sprintf('sample_%03d', $n); }, range(50, 59) );

print_r($a);

?>

Will result:

Array
(
    [0] => sample_050
    [1] => sample_051
    [2] => sample_052
    [3] => sample_053
    [4] => sample_054
    [5] => sample_055
    [6] => sample_056
    [7] => sample_057
    [8] => sample_058
    [9] => sample_059
)

down

chris at laflash dot org ¶

17 years ago


Quick HTML menus with minimum and maximum sets of years:

<?php 
    /* 
    ** Quick HTML menus with minimum and maximum sets of years.
    ** @author Chris Charlton <chris@laflash.org>
    ** @license FREE!
    */

    // Years range setup
    $year_built_min = 1900;
    $year_built_max = date("Y");
?>
<select id="yearBuiltMin" size="1">
    <?php // Generate minimum years 

        foreach (range($year_built_min, $year_built_max) as $year) { ?>
        <option value="<?php echo($year); ?>"><?php echo($year); ?></option>
        <?php } ?>
</select>

<select id="yearBuiltMax" size="1">
      <?php // Generate max years 

        foreach (range($year_built_max, $year_built_min) as $year) { ?>
        <option value="<?php echo($year); ?>"><?php echo($year); ?></option>
        <?php } ?>
</select>

down

m0sh3 at hotmail dot com ¶

17 years ago


Here's how i use it to check if array is associative or not:

<?php

if (array_keys($arr)===range(0, sizeof($arr)-1)) {
// not associative array

} else {
// associative array 

}

?>

down

Ray.Paseur often uses Gmail ¶

11 years ago


Interestingly, these two statements produce identical 26-character alphabet arrays.

<?php
$arr = range('A',  'Z');
$arr = range('AA', 'ZZ');

down

dries at volta dot be ¶

12 years ago


Ever wanted to generate an array with a range of column names for use in Excel file related parsing?
I've wrote a function that starts at the A column and adds column names up until the column you specified.

<?php

/**
 * This function creates an array with column names up until the column
 * you specified.
*/
function createColumnsArray($end_column, $first_letters = '')
{
  $columns = array();
  $length = strlen($end_column);
  $letters = range('A', 'Z');

  // Iterate over 26 letters.
  foreach ($letters as $letter) {
      // Paste the $first_letters before the next.
      $column = $first_letters . $letter;

      // Add the column to the final array.
      $columns[] = $column;

      // If it was the end column that was added, return the columns.
      if ($column == $end_column)
          return $columns;
  }

  // Add the column children.
  foreach ($columns as $column) {
      // Don't itterate if the $end_column was already set in a previous itteration.
      // Stop iterating if you've reached the maximum character length.
      if (!in_array($end_column, $columns) && strlen($column) < $length) {
          $new_columns = createColumnsArray($end_column, $column);
          // Merge the new columns which were created with the final columns array.
          $columns = array_merge($columns, $new_columns);
      }
  }

  return $columns;
}

?>

Usage:

<?php

// Return an array with all column names from A until and with BI.
createColumnsArray('BI');

?>

down

me at phpscott dot com ¶

12 years ago


So, I needed a quick and dirty way to create a dropdown select for hours, minutes and seconds using 2 digit formatting, and to create those arrays of data, I combined range with array merge..



<?php

$prepend = array('00','01','02','03','04','05','06','07','08','09');

$hours     = array_merge($prepend,range(10, 23));

$minutes     = array_merge($prepend,range(10, 59));

$seconds     = $minutes;

?>



Super simple.

down

captvanhalen at gmail dot com ¶

16 years ago


Here is a home rolled range() function that uses the step feature for those unfortunate souls who cannot use PHP5:

<?php
function my_range( $start, $end, $step = 1) {

    $range = array();

    foreach (range( $start, $end ) as $index) {

        if (! (($index - $start) % $step) ) {
            $range[] = $index;
        }
    }

    return $range;
}
?>

down

moficer at host dot sk ¶

8 years ago


php 5.6.16

<?php
var_export(range('Z', 'a'));

/*
array (
  0 => 'Z',
  1 => '[',
  2 => '\\',
  3 => ']',
  4 => '^',
  5 => '_',
  6 => '`',
  7 => 'a',
)
 */

down

jay at NOspam dot myd3 dot com ¶

15 years ago


This is a modified version of thomas' range_string() function. It's simpler, cleaner, and more robust, but it lacks the advanced features his function had, hopefully it will be of assitance to someone.

Examples:

    input: "1, 2, 3, 4, 5, 6" --> output: 1, 2, 3, 4, 5, 6
    input: "1-6" --> output: 1, 2, 3, 4, 5, 6
    input: "1-6" --> output: 1, 2, 3, 4, 5, 6
    input: "1 - -6" --> output: 1, 2, 3, 4, 5, 6
    input: "0 - 0" --> output: 0
    input: "1, 4-6, 2" --> output: 1, 2, 4, 5, 6
    input: "6,3-1" --> output: 1, 2, 3, 6

<?php

define('RANGE_ARRAY_SORT', 1);
define('RANGE_ARRAY', 2);
define('RANGE_STRING_SORT', 3);
define('RANGE_STRING', 4);

function range_string($range_str, $output_type = RANGE_ARRAY_SORT)
{
    // Remove spaces and nother non-essential characters
    $find[]    = "/[^\d,\-]/";
    $replace[] = "";
    
    // Remove duplicate hyphens
    $find[]    = "/\-+/";
    $replace[] = "-";
    
    // Remove duplicate commas
    $find[]    = "/\,+/";
    $replace[] = ",";
    
    $range_str = preg_replace($find, $replace, $range_str);

    // Remove any commas or hypens from the end of the string
    $range_str = trim($range_str,",-");
    
    $range_out = array();
    $ranges    = explode(",", $range_str);
    
    foreach($ranges as $range)
    {
        
        if(is_numeric($range) || strlen($range) == 1)
        {
            // Just a number; add it to the list.
            $range_out[] = (int) $range;
        }
        else if(is_string($range))
        {
            
            // Is probably a range of values.
           $range_exp = preg_split("/(\D)/",$range,-1,PREG_SPLIT_DELIM_CAPTURE);
        
            $start = $range_exp[0];
            $end   = $range_exp[2];
        
            if($start > $end)
            {
                for($i = $start; $i >= $end; $i -= 1)
                {
                    $range_out[] = (int) $i;
                }
            }
            else
            {
                for($i = $start; $i <= $end; $i += 1)
                {
                    $range_out[] = (int) $i;
                }
            }
            
        }
    }
    
    switch ($output_type) {
        case RANGE_ARRAY_SORT:
            $range_out = array_unique($range_out);
            sort($range_out);
            
        case RANGE_ARRAY:
            return $range_out;
            break;
            
        case RANGE_STRING_SORT:
            $range_out = array_unique($range_out);
            sort($range_out);
            
        case RANGE_STRING:
        
        default:
            return implode(", ", $range_out);
            break;
    }
}

// Sample Usage:
$range = range_string("6, 3-1");

?>

down

qz ¶

8 years ago


If you're looking to fill an array to get a hash with 0-9 numerical values, using
range(0,9);
is a faster solution compared to 
array_fill(0, 10, '');

down

krdr dot mft at gmail dot com ¶

11 years ago


I've been introduced with range() function not so long ago, and I found that examples about it is somewhat wrong, even inefficient:

<?php
$o = "";
$time_start = microtime(true); 
foreach(range(1, 10000) as $val) { 
    $o .= $val; 
} 
$time_end = microtime(true);
$time = $time_end - $time_start; 
echo 'rangein: '.$time.'<br />'; 

$o = "";
$time_start = microtime(true); 
$a = range(1, 10000);
foreach($a as $val) { 
    $o .= $val;  
} 
$time_end = microtime(true);
$time = $time_end - $time_start; 
echo 'rangeout: '.$time.'<br />'; 

?>

Which gives results:

rangein: 0.0025348663330078
rangeout: 0.0019199848175049

In some cases difference is even bigger and proportional to the range generated. I suppose that results of range() are cached/hashed.

Note: execution order does affects execution times, but difference still exists

down

manuel at levante dot de ¶

18 years ago


<?php
function srange ($s) {
  preg_match_all("/([0-9]{1,2})-?([0-9]{0,2}) ?,?;?/", $s, $a);
  $n = array ();
  foreach ($a[1] as $k => $v) {
    $n  = array_merge ($n, range ($v, (empty($a[2][$k])?$v:$a[2][$k])));
  }
  return ($n);
}

$s = '1-4 6-7 9-10';
print_r(srange($s));
?>

Return:
Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 6
    [5] => 7
    [6] => 9
    [7] => 10
)

down

VivienG ¶

1 year ago


They forgot to say something.
If the ending value not encounter the last sequence, the function return false.
In other words : 
Given a int $n, if ( $start + $n * $step ) < $end and  ( $start + ( $n + 1 ) * $step ) > $end, the function doen't give the maximum possible range, it returns a boolean.
So the last range number HAVE TO BE the end number.

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mohammed dot hussein dot mahmoud at gmail dot com ¶

2 years ago


You could use negative numbers in place of the `step` parameter. You need to make sure that the `start` is bigger than `end`. Note that range() function in php generates the range inclusive, i.e. it also includes the `end` parameter and not just up to it but not including it like most other languages.
The following snippet of code should explain what I mean about negative steps:

<?php

// 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, 0
print_r(range(100, 0, -10));

?>

What happens basically is that the range function does not really care about what is bigger or smaller, it just adds the step to the start and appends that to the a temp result variable as long as it did not reach the end param value. In this case, adding negative numbers is like minus (computers do that for 2's complement under the hood.) This will cause the number to go from 100 to 90 and then the function will check if 90 reached 0 yet. Since it wouldn't have done that, it will keep adding -step (-10 in that case) to the latest result (i.e. 90) and so on and so forth.

Since range() is said to be better and faster than array_fill() I believe it was important for me to try it out and actually post this note on the official documentation just to make sure people can use this.

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lsblsb at gmx dot de ¶

10 years ago


I needed a function, that creates a letter range with arbitrary length.
You specify via the $length parameter, how many entries you need.
Logic is analog to the logic of the column-titles in a calc-sheet.

<?php

/**
  * create a letter range with arbitrary length
  * @param int $length
  * @return array
  */
function createLetterRange($length)
{
    $range = array();
    $letters = range('A', 'Z');
    for($i=0; $i<$length; $i++)
    {
        $position = $i*26;
        foreach($letters as $ii => $letter)
        {
            $position++;
            if($position <= $length)
                $range[] = ($position > 26 ? $range[$i-1] : '').$letter;
        }
    }
    return $range;
}
?>

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-1

pyetrosafe at gmail dot com ¶

11 years ago


To create a simple array or a multidimensional array with defined size and null values, use this expression:

<?php

$SimpleArray = array_map(function($n) { return null; }, range(1, 3) );
$MultiArray = array_map(function($n) { return array_map(function($n) { return null; }, range(1, 2) ); }, range(1, 3) );

var_dump($SimpleArray);
var_dump($MultiArray);

// And will print:
?>
>>$SimpleArray
array(3) {
  [0]=>  NULL
  [1]=>  NULL
  [2]=>  NULL
}

>>$MultiArray
array(3) {
  [0]=>  array(2) {
    [0]=>    NULL
    [1]=>    NULL
  }
  [1]=>  array(2) {
    [0]=>    NULL
    [1]=>    NULL
  }
  [2]=>  array(2) {
    [0]=>    NULL
    [1]=>    NULL
  }
}

?>

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-1

derek at php dot net ¶

19 years ago


This should emulate range() a little better.

<?php

function range_wroar($low, $high, $step = 1) {

    $arr = array();

    $step = (abs($step)>0)?abs($step):1;

    $sign = ($low<=$high)?1:-1;

    if(is_numeric($low) && is_numeric($high)) {

        //numeric sequence

        for ($i = (float)$low; $i*$sign <= $high*$sign; $i += $step*$sign)

            $arr[] = $i;

    }    else    {

        //character sequence

        if (is_numeric($low)) 

            return $this->range($low, 0, $step);

        if (is_numeric($high))

            return $this->range(0, $high, $step);

        $low = ord($low);

        $high = ord($high);

        for ($i = $low; $i*$sign <= $high*$sign; $i += $step*$sign) {

                

            $arr[] = chr($i);

        }

    }

    return $arr;

}

?>

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-2

emory underscore smith at hotmail ¶

19 years ago


since its not stated explicitly above, thought id point out that you arent limited to using integers.

however, be careful when doing so, as you might not get the range you expect!

to illustrate:

<?php
$am = range(500,1600,10);
$fm = range(88.1,107.9,.2);
print_r($am);
print_r($fm);
?>

print_r($am) yields the expected result:
             
Array
(
    [0] => 500
    [1] => 510
    [2] => 520
    ...
    [109] => 1590
    [110] => 1600
)

print_r($fm), however, falls a bit (1%) short:

Array
(
    [0] => 88.1
    [1] => 88.3
    [2] => 88.5
    ...
    [97] => 107.5
    [98] => 107.7
)
    
so, if you want to use a non-integral step size params for numeric ranges, be sure to account for fp representation accuracy and error accumulation; a step size of something like pi or 1/10 could spell disaster for a large range. if in doubt, use integral steps and divide ... something like <?php range(88.1,108,.2) ?> might work to recover 107.9, but would not be scalable like, say <?php array_map(create_function('$x','return $x/10;'),range(881,1079,2)) ?>.

-emory

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-2

subscription101 at hotmail dot com ¶

18 years ago


A much simpler way of creating a range of even numbers is by starting with an even number:

<?php

    range(2, 10, 2);

?>

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-2

j dot gizmo at aon dot at ¶

20 years ago


i figured i'd add some more functionality to the myRange() functions below.
now you can, besides giving a $step parameter,
1. count backwards
2. count with letters
3. give whatever parameter you want, there's nothing (i know of) that will cause an endless loop (try a negative $step for the previous function....)

<?php
function myRange($num1, $num2, $step=1)
{
    if (is_numeric($num1) && is_numeric($num2))
    {
        //we have a numeric range
        $step = ( abs($step)>0 ? abs($step) : 1 ); //make $step positive
        $dir = ($num1<=$num2 ? 1 : -1); //get the direction
        for($i = (float)$num1; $i*$dir <= $num2*$dir; $i += $step*$dir)
        {
            $temp[] = $i;
        }
    }
    else
    {
        //we have a character range
        $num1=ord((string)$num1); //convert to ascii value
        $num2=ord((string)$num2);
        $step = ( abs($step)>0 ? abs($step) : 1 ); //make $step positive
        $dir = ($num1<=$num2 ? 1 : -1); //get direction
        for($i = $num1; $i*$dir <= $num2*$dir; $i += $step*$dir)
        {
            $temp[] = chr($i);
        }
    }
    return $temp;
}

print_r(myRange( 1, 3, 0.5 )); //you can use fractional steps
print_r(myRange( "a", "k", 3 )); //or count letters
print_r(myRange( "5", "9" )); //numbers are detected even if hidden in strtings
print_r(myRange( "!", "%", 1/pi() )); //or mess around with senseless parameters

?>

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-3

unicod3 at hotmail dot com ¶

10 years ago


a function to get column index by letter  
 
function getColumnNumber($char){
    $alphabet = range('a','z');
    $alphabet2 = range('a','z');
    $newAlphabet = $alphabet;
    foreach($alphabet as $k => $r)
    {
        foreach($alphabet2 as $row){
            $newAlphabet[] = $r.$row;
        }
    }
    $key = array_search($char, $newAlphabet);
    return ($key !== false) ? $key : null;
}

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-5

Aram Kocharyan ¶

13 years ago


Here's a function to generate ranges from strings:

<?php

/*  Creates an array of integers based on a given range string of format "int - int"
    Eg. range_str('2 - 5'); */
function range_str($str) {
    preg_match('#(\\d+)\\s*-\\s*(\\d+)#', $str, $matches);
    if ( count($matches) == 3 ) {
        return range($matches[1], $matches[2]);
    }
    return FALSE;
}

// Test
$array = range_str(' 2 - 4 ');
print_r($array);

?>

This outputs:

Array
(
    [0] => 2
    [1] => 3
    [2] => 4
)

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