php foreach组的结果由3组字符组成

Question

I am trying to group some foreach results based on the first 3 sets of characters.

For example i am currently listing sku codes for products and they look like this:

REF-MUSBOM-0500-ORA
REF-PROCOF-0001-LAT
REF-WHEREF-0001-TRO
REF-WHEREF-0001-ORA
REF-SHAKER-0700-C/B
REF-CREMON-0100-N/A
REF-GLUSUL-0090-N/A
REF-CRECAP-0090-N/A
REF-ALBFER-0120-N/A
REF-TSHCOT-LARG-BLK
REF-TSHCOT-MEDI-BLK
REF-ALBMAG-0090-N/A
REF-GYMJUG-2200-N/A
REF-OMEGA3-0090-N/A
REF-NEXGEN-0060-N/A
REF-VITAD3-0100-N/A
REF-SSSHAK-0739-N/A
REF-GINKGO-0090-N/A
REF-DIGEZY-0090-N/A
REF-VEST00-MEDI-N/A
REF-VEST00-LARG-N/A
REF-CREMON-0250-N/A
REF-MSM----0250-N/A
REF-GRNTEA-0100-N/A
REF-COLOST-0100-N/A
REF-GLUCHO-0090-N/A
REF-ZINCMA-0100-N/A
REF-BETALA-0250-N/A
REF-DRIBOS-0250-N/A
REF-HMB000-0090-N/A
REF-ALACID-0090-N/A
REF-CLA000-0090-N/A
REF-ACETYL-0090-N/A
REF-NXGPRO-0090-N/A
REF-LGLUTA-0250-N/A
REF-BCAA20-0200-N/A
REF-FLAPJA-0012-ACR
REF-FLAPJA-0012-MAP
REF-LCARNI-0100-N/A
REF-CORDYC-0090-N/A
REF-CREMON-0500-N/A
REF-BCAAEN-0330-APP
REF-PREWKT-0300-FPU
REF-TESFUS-0090-N/A
REF-AMIIFUS-0300-GAP
REF-AMIIFUS-0300-WME
REF-BCAINT-0400-FPU
REF-KRILLO-0090-N/A
REF-AMIIFUS-0300-PLE
REF-AMIIFUS-0300-FPU
REF-BCAINT-0400-WME
REF-ENZQ10-0090-N/A
REF-THERMO-0100-N/A
REF-LGLUTA-0500-N/A
REF-RBAR00-0012-DCB
REF-RBAR00-0012-PBC
REF-RBAR00-0012-WCR
REF-IMHEAV-2200-CHO
REF-PROCOF-0012-N/A
REF-DIEPRO-0900-STR
REF-DIEPRO-0900-BOF
REF-DIEPRO-0900-CHO
REF-INWPRO-0900-VAN
REF-INWPRO-0900-BOF
REF-INWPRO-0900-BCS
REF-INWPRO-0900-CHO
REF-INWPRO-0900-CMI
REF-INWPRO-0900-RAS
REF-INWPRO-0900-STR
REF-INWPRO-0900-CIN
REF-INWPRO-0900-CPB
REF-EGGPRO-0900-CHO
REF-EGGPRO-0900-VAN
REF-MICCAS-0909-CHO
REF-MICCAS-0909-CMI
REF-MICCAS-0909-VAN
REF-MICCAS-0909-STR
REF-BCAA50-0500-N/A
REF-MICWHE-0909-STR
REF-MICWHE-0909-VAN
REF-MICWHE-0909-CHIO
REF-MICWHE-0909-BAN
REF-1STOXT-2030-STR
REF-1STOXT-2030-VAN
REF-1STOXT-2030-CHO
REF-MUSBOM-0600-BCH
REF-MUSBOM-0600-FPU
REF-MUSBCF-0600-BCH
REF-MUSBCF-0600-FPU
REF-VEGANP-2100-STR
REF-VEGANP-2100-CHO
REF-INMPRO-2270-CPB
REF-DIETMR-2400-CPB
REF-INMPRO-2270-SCR
REF-INMPRO-2270-VIC
REF-MATRIX-1800-FRU
REF-INMPRO-2270-BOF
REF-MATRIX-1800-CHO
REF-INMPRO-2270-CHO
REF-ONESTO-2100-CHO

In the above list there are 2 skus which are:

REF-WHEREF-0001-TRO
REF-WHEREF-0001-ORA

The first 3 sets of characters split by - are the same. What would be the best approach of grouping all results leaving me an array something like this:

Array
(
[REF-WHEREF-0001] => Array
    (
        [0] => REF-WHEREF-0001-TRO
        [1] => REF-WHEREF-0001-ORA

    )
)

Answer 1

Are the first 3 groups (excluding the multiple -) always 13 characters? Then do something like this:

<?php
$arr = ["REF-MUSBOM-0500-ORA",
    "REF-PROCOF-0001-LAT",
    "REF-WHEREF-0001-TRO",
    "REF-WHEREF-0001-PPL"];

$resultArr = [];
foreach ($arr as $sku) {
    $resultArr[substr($sku, 0, 15)][] = $sku;
}

var_dump($resultArr);

If that length varies you might want to work with a regex or the strpos() of the third -.

I must say that I think you could come up with this yourself, since you were already thinking in the right direction i.e. foreach()

EDIT: Because I found other solutions more elegant looking, I decided to compare efficiency. This solution is a lot faster than the other ones.