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))
(PHP 4, PHP 5, PHP 7, PHP 8)
range — 根据范围创建数组，包含指定的元素
建立一个包含指定范围单元的数组。
如果 start 和 end 都是 string，step
是 int，则生成的数组是字节序列，否则，生成的数组将是数字序列。
如果 start 小于或等于 end，则为递增序列，否则为递减序列。
返回 array，由元素组成的序列，其中第一个元素为 start，最后一个元素为
end，序列中每个元素之间的差值为 step。
返回的数组的最后一个元素是 end 或序列中的前一个元素，具体取决于 step。
如果 start 和 end 都是 string，并且
step 是 int，则生成的数组将是字节序列，通常是拉丁 ASCII 字符。
如果 start、end 或 step 是
float，则生成的数组将是 float 序列。
否则，生成的数组将是 int 序列。
step 是 0，则抛出 ValueError。
start、end 或 step 不是
is_finite()，则抛出 ValueError。
step 是负数，但生成的范围是递增的（例如 $start <=
$end），则抛出 ValueError。
start 或 end 是空字符串 ''，则发出
E_WARNING 并将空字符串解释为 0。
start 或 end 不是一个数字字符串，并且多于一个字节，将发出 E_WARNING。
start 或 end 是字符串，并且由于另一个边界值是数字而默默转换为
int，将发出 E_WARNING。
step 是 float，并且 start 和 end
不是数字字符串，将发出 E_WARNING。
| 版本 | 说明 |
|---|---|
| 8.3.0 |
如果 start 和 end 都是字符串，然后 range()
现在将始终生成字节 array。之前如果其中一个边界值是数字字符串，然后另外一个边界值也会默默转换为 int。
|
| 8.3.0 |
如果 start 或 end 是字符串，并且由于另一个边界值是数字而默默转换为
int，现在将发出 E_WARNING。
|
| 8.3.0 |
如果 start 或 end 是多于一个字节的非数字字符串，现在将发出 E_WARNING。
|
| 8.3.0 |
如果 start 或 end 是空字符串，现在将发出 E_WARNING。
|
| 8.3.0 |
如果 step 是不带小数部分的 float，将解释为 int。
|
| 8.3.0 |
如果 step 是负数，当生成的范围是递增时，现在将抛出 ValueError。
|
| 8.3.0 |
如果 step 不是有限数值（finite），现在将抛出 ValueError。
|
| 8.3.0 |
如果 start 或 end 是 array、object 或
resource，现在将会抛出 TypeError。之前会默默地转换为 int。
|
示例 #1 range() 示例
<?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;
?>以上示例会输出：
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
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))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.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.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" }
?><?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() - $start_time).' seconds.',
);
}
var_dump(natural_prime_numbers(range(0, 11))); // here the range() function ;-)
// Result:
// array (size=3)
// 'length_prime_numbers' => int 5
// 'prime_numbers' =>
// array (size=5)
// 0 => int 2
// 1 => int 3
// 2 => int 5
// 3 => int 7
// 4 => int 11
// 'print' => string '
// O número 2 dividido pelo número 1 é igual a: 2
// O número 2 dividido pelo número 2 é igual a: 1
// O número 3 dividido pelo número 1 é igual a: 3
// O número 3 dividido pelo número 2 é igual a: 1.5
// O número 3 dividido pelo número 3 é igual a: 1
// O número 5 dividido pelo número 1 é igual a: 5
// O número 5 dividido pelo número 2 é igual a: 2.5
// O número 5 dividido pelo número 3 é igual a: 1.6666666666667
// O número 5 dividido pelo número 4 é igual a: 1.25
// O número 5 dividido pelo '...
// **************************** //
//
// * Remember that the function is recursive, that is: a range of 5000 takes more than 1 minute on a processor Intel® Core™ i5-8250U (3.40 GHz).
//
// **************************** //
?>The function "range" is very useful to get an array of characters as range('C','R') does.
At work, I had to extend the function range($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 $amount;
}
?>foreach(range()) whilst efficiant in other languages, such as python, it is not (compared to a for) in php*.
php is a C-inspired language and thus for is entirely in-keeping with the lanuage aethetic to use it
<?php
//efficiant
for($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()).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
)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
)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($year); ?></option>
<?php } ?>
</select>Here's how i use it to check if array is associative or not:
<?php
if (array_keys($arr)===range(0, sizeof($arr)-1)) {
// not associative array
} else {
// associative array
}
?>Interestingly, these two statements produce identical 26-character alphabet arrays.
<?php
$arr = range('A', 'Z');
$arr = range('AA', 'ZZ');Ever wanted to generate an array with a range of column names for use in Excel file related parsing?
I've wrote a function that starts at the A column and adds column names up until the column you specified.
<?php
/**
* This function creates an array with column names up until the column
* you specified.
*/
function createColumnsArray($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');
?>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.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 $range;
}
?>php 5.6.16
<?php
var_export(range('Z', 'a'));
/*
array (
0 => 'Z',
1 => '[',
2 => '\\',
3 => ']',
4 => '^',
5 => '_',
6 => '`',
7 => 'a',
)
*/This is a modified version of thomas' range_string() function. It's simpler, cleaner, and more robust, but it lacks the advanced features his function had, hopefully it will be of assitance to someone.
Examples:
input: "1, 2, 3, 4, 5, 6" --> output: 1, 2, 3, 4, 5, 6
input: "1-6" --> output: 1, 2, 3, 4, 5, 6
input: "1-6" --> output: 1, 2, 3, 4, 5, 6
input: "1 - -6" --> output: 1, 2, 3, 4, 5, 6
input: "0 - 0" --> output: 0
input: "1, 4-6, 2" --> output: 1, 2, 4, 5, 6
input: "6,3-1" --> output: 1, 2, 3, 6
<?php
define('RANGE_ARRAY_SORT', 1);
define('RANGE_ARRAY', 2);
define('RANGE_STRING_SORT', 3);
define('RANGE_STRING', 4);
function range_string($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");
?>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 existsIf 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, '');<?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
)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.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.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 $range;
}
?>This should emulate range() a little better.
<?php
function range_wroar($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;
}
?>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
}
}
?>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)) ?>.
-emoryA much simpler way of creating a range of even numbers is by starting with an even number:
<?php
range(2, 10, 2);
?>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 $temp;
}
print_r(myRange( 1, 3, 0.5 )); //you can use fractional steps
print_r(myRange( "a", "k", 3 )); //or count letters
print_r(myRange( "5", "9" )); //numbers are detected even if hidden in strtings
print_r(myRange( "!", "%", 1/pi() )); //or mess around with senseless parameters
?>a function to get column index by letter
function getColumnNumber($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) ? $key : null;
}Here's a function to generate ranges from strings:
<?php
/* Creates an array of integers based on a given range string of format "int - int"
Eg. range_str('2 - 5'); */
function range_str($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
)