range

(PHP 4, PHP 5, PHP 7)

range — 根据范围创建数组，包含指定的元素

说明

array range ( mixed $start , mixed $end [, number $step = 1 ] )

建立一个包含指定范围单元的数组。

参数

start

序列的第一个值。

end

序列结束于 end 的值。

step

如果设置了步长 step，会被作为单元之间的步进值。step 应该为正值。不设置step 则默认为 1。

返回值

返回的数组中从 start 到 end （含 start 和 end）的单元。

范例

Example #1 range() 例子

<?php
// array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
foreach (range(0, 12) as $number) {
    echo $number;
}

//  step 参数
// array(0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100)
foreach (range(0, 100, 10) as $number) {
    echo $number;
}

// 字符序列的使用
// array('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i');
foreach (range('a', 'i') as $letter) {
    echo $letter;
}
// array('c', 'b', 'a');
foreach (range('c', 'a') as $letter) {
    echo $letter;
}
?>

注释

Note:

字符序列值仅限单个字符。 如果长度大于1，仅仅使用第一个字符。

参见

User Contributed Notes

luca.favorido ATgmailDOT com 28-Jun-2016 04:58
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;
}
?>
qz 20-Jan-2016 08:58
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, '');
moficer at host dot sk 16-Jan-2016 12:17
php 5.6.16

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

/*
array (
  0 => 'Z',
  1 => '[',
  2 => '\\',
  3 => ']',
  4 => '^',
  5 => '_',
  6 => '`',
  7 => 'a',
)
 */
Alien426 29-Oct-2015 11:09
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" }
?>
unicod3 at hotmail dot com 16-Oct-2014 02:43
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;
}
lsblsb at gmx dot de 01-May-2014 12:09
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;
}
?>
php at keith tyler dot com 27-Feb-2014 07:22
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.
jazzduck AT gmail DOT com 22-Jan-2014 05:32
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
)
pyetrosafe at gmail dot com 27-Sep-2013 10:36
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
  }
}

?>
krdr dot mft at gmail dot com 20-Aug-2013 06:48
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
Ray.Paseur often uses Gmail 07-Jun-2013 12:16
Interestingly, these two statements produce identical 26-character alphabet arrays.

<?php
$arr = range('A',  'Z');
$arr = range('AA', 'ZZ');
gtisza at gmail dot com 25-Apr-2013 07:27
You might expect range($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.
Palz 30-Oct-2012 07:59
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))
ktamas77 at gmail dot com 04-Aug-2012 07:59
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
)
me at phpscott dot com 24-May-2012 02:37
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.
dries at volta dot be 09-Feb-2012 08:30
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');

?>
Aram Kocharyan 28-Feb-2011 04:58
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
)
jay at NOspam dot myd3 dot com 30-Apr-2009 02:54
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");

?>
ThinkMedical at Gmail dot com 26-Aug-2008 02:11
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()).
captvanhalen at gmail dot com 27-Mar-2008 07:33
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;
}
?>
chris at laflash dot org 10-May-2007 01:47
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>
m0sh3 at hotmail dot com 02-Mar-2007 02:46
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

}

?>
manuel at levante dot de 07-Nov-2006 02:25
<?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
)
subscription101 at hotmail dot com 08-Jan-2006 03:36
A much simpler way of creating a range of even numbers is by starting with an even number:

<?php

    range(2, 10, 2);

?>
emory underscore smith at hotmail 21-Aug-2005 04:53
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
derek at php dot net 08-May-2005 03:13
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;
}
?>
j dot gizmo at aon dot at 23-Sep-2004 01:23
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

?>