explode an array of delimited strings into two arrays

问题

I have the following array:

Array
    (
        [0] => 10-7
        [1] => 11-3
        [2] => 11-7
        [3] => 12-3
        [4] => 12-7
        [5] => 13-3
        [6] => 13-7
        [7] => 14-3
        [8] => 14-7
        [9] => 15-7
    )

that I need to split into two arrays using "-" as delimiter:

Array
    (
        [0] => 10
        [1] => 11
        [2] => 11
        [3] => 12
        [4] => 12
        [5] => 13
        [6] => 13
        [7] => 14
        [8] => 14
        [9] => 15
    )

and

Array
    (
        [0] => 7
        [1] => 3
        [2] => 7
        [3] => 3
        [4] => 7
        [5] => 3
        [6] => 7
        [7] => 3
        [8] => 7
        [9] => 7
    )

Is there anything like array_explode that does what I want? or a combination of php array functions? I'd like to do this without going through my own for/each loop, if possible, or at least minimize having to reinvent the wheel when something (pseudo)in-built is already out there. I already did this with a for loop. But I can't shake the feeling that there's a more elegant way that smartly uses array functions or anything of that kind. Thanks so much, guys.

Additional info:

Not sure if it matters, but I'm actually after the unique values in the resulting two arrays:

Array
    (
        [0] => 10
        [1] => 11
        [2] => 12
        [3] => 13
        [4] => 14
        [5] => 15
    )

and

Array
    (
        [0] => 7
        [1] => 3
    )

The unique values don't need to be sorted, the keys may be preserved or not, and the legal values of the first array range from 0 to 23, while those of the second 1 to 7. However it's possible to have values other than these (0 to 23 and 1 to 7 or even undelimited stray strings or other data types beyond my control), which I would definitely want to throw out.

回答1:

The magic bullet you're looking for is array_reduce(), e.g. (PHP 5.3+):

list( $left, $right ) = array_reduce( $input,
  function( $memo, $item ) {
    list( $l, $r ) = explode( '-', $item );
    $memo[0][$l] = $memo[1][$r] = true;
    return $memo;
  },
  array( array(), array() )
);

var_dump( array_keys( $left ), array_keys( $right ) );

You can see it in action here.

With PHP <5.3 you'll have to declare the function ahead of time:

function my_reducer( $memo, $item ) {
  list( $l, $r ) = // ...
  // ... as above ...
}

list( $left, $right ) = array_reduce(
  $input, 'my_reducer',
  array( array(), array() )
);

回答2:

http://codepad.org/TpVUIhM7

<?php
    $array = array('7-10','7-11','5-10');
    foreach($array as $a){list($x[], $y[]) = explode("-", $a);}
    print_r(array_unique($x));
    print_r(array_unique($y));
?>

回答3:

Here Is your Solution, Try to implement following code.

Should work for you.

$main_array =   array( 
        '0' => '10-7',
        '1' => '11-3',
        '2' => '11-7',
        '3' => '12-3',
        '4' => '12-7',
        '5' => '13-3',
        '6' => '13-7',
        '7' => '14-3',
        '8' => '14-7',
        '9' => '15-7',
        );

foreach($main_array as $key=>$value)
{
    $arr_value      =   explode('-',$value);
    $arr_temp1[]    =   $arr_value[0];
    $arr_temp2[]    =   $arr_value[1];  
}
$arr_temp1_unique   = array_unique($arr_temp1);
$arr_temp2_unique   = array_unique($arr_temp2);


print "<pre>";
print_r($main_array);
print_r($arr_temp1);
print_r($arr_temp2);

print_r($arr_temp1_unique);
print_r($arr_temp2_unique);
print "</pre>";

回答4:

As far as I know, there is no suitable PHP function that you can use in this situation.

Functions like array_walk() and array_map() result in a single array, not in multiple arrays.

You said you already have tried a sollution with a loop, but for the sake of helping, here is how I would solve this:

//$data contains the array you want to split
$firstItems = array();
$secondItems = array();

foreach($data as $item)
{
    list($first, $second) = explode('-', $item, 2);
    $firstItems[$first] = true;
    $secondItems[$second] = true;    
}

//Now you can get the items with array_keys($firstItems) and array_keys($secondItems);

I'm treating the PHP array as a set by setting the keys instead of the values. This makes that you don't have to use array_unique() to get the unique items.

回答5:

Try:

foreach($old_array as $array){
    $new_2d_array = explode('-', $array);
    $new_array_1[] = $new_2d_array[0];
    $new_array_2[] = $new_2d_array[1];  
}
$new_array_1 = array_unique($new_array_1);
$new_array_2 = array_unique($new_array_2);

来源：https://stackoverflow.com/questions/10714188/explode-an-array-of-delimited-strings-into-two-arrays

标签

php

arrays

function

explode