{"id":373,"date":"2024-01-29T09:07:31","date_gmt":"2024-01-29T08:07:31","guid":{"rendered":"https:\/\/gdm.sosthe.sk\/?page_id=373"},"modified":"2024-01-29T09:07:31","modified_gmt":"2024-01-29T08:07:31","slug":"praca-s-polami","status":"publish","type":"page","link":"https:\/\/gdm.sosthe.sk\/?page_id=373","title":{"rendered":"Pr\u00e1ca s po\u013eami"},"content":{"rendered":"

Medzi najz\u00e1kladnej\u0161ie funkcie pre pr\u00e1cu s po\u013eom patr\u00ed funkcia\u00a0count()<\/em>.<\/p>\n

Funkcia\u00a0count($pole)<\/em>\u00a0spo\u010d\u00edta po\u010det prvkov po\u013ea\u00a0$pole<\/em>.<\/p>\n

Pr\u00edklad:<\/em><\/p>\n

<?php\r\n $den = Array(\"1\" => \"Pondelok\",\r\n     \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"2\" => \"Utorok\",\r\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"3\" => \"Streda\",\r\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"4\" => \"\u0160tvrtok\",\r\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"5\" => \"Piatok\",\r\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"6\" => \"Sobota\",\r\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"0\" => \"Nede\u013ea\");\r\n for($i=0; $i<count($den);\r\n  $i++) echo $den[$i].\"<br \/>\";\r\n echo count($den);\r\n?><\/pre>\n
V\u00fdsledok pr\u00edkladu:<\/em><\/p>\n
Nede\u013ea
\nPondelok
\nUtorok
\nStreda
\n\u0160tvrtok
\nPiatok
\nSobota
\n7<\/p>\n
Funkcia\u00a0each($pole)<\/em>\u00a0vracia aktu\u00e1lny k\u013e\u00fa\u010d a p\u00e1r hodn\u00f4t z po\u013ea\u00a0$pole<\/em>\u00a0a pos\u00fava kurzor po\u013ea. Tento p\u00e1r sa vracia v \u0161tvor-prvkovom poli s k\u013e\u00fa\u010dami\u00a00<\/em>,\u00a01<\/em>,\u00a0key<\/em>\u00a0a\u00a0value<\/em>. Prvky\u00a00<\/em>\u00a0a\u00a0key<\/em>\u00a0obsahuj\u00fa k\u013e\u00fa\u010dov\u00fd n\u00e1zov prvku po\u013ea a\u00a01<\/em>\u00a0a\u00a0value<\/em>\u00a0obsahuj\u00fa d\u00e1ta.<\/p>\n
Ak vn\u00fatorn\u00fd ukazovate\u013e pre pole ukazuje na koniec obsahu po\u013ea,\u00a0each()<\/em>\u00a0vracia\u00a0FALSE<\/em>.<\/p>\n
Pr\u00edklad:<\/em><\/p>\n
$foo = array (\"bob\", \"fred\", \"jussi\", \"jouni\", \"egon\", \"marliese\");\r\n$bar = each ($foo);<\/pre>\n
$bar<\/em>\u00a0teraz obsahuje n\u00e1sleduj\u00face p\u00e1ry k\u013e\u00fa\u010dov\/hodn\u00f4t:<\/p>\n
0 => 01 => \u201abob\u2019key => 0value => \u201abob\u2018<\/p>\n
Pr\u00edklad:<\/p>\n
$foo = array (\"Robert\" => \"Bob\", \"Seppo\" => \"Sepi\");\r\n$bar = each ($foo);<\/pre>\n
$bar<\/em>\u00a0teraz obsahuje n\u00e1sleduj\u00face p\u00e1ry k\u013e\u00fa\u010dov\/hodn\u00f4t:<\/p>\n
0 => \u201aRobert\u20191 => \u201aBob\u2019key => \u201aRobert\u2019value => \u201aBob\u2018<\/p>\n
each()<\/em>\u00a0sa v\u00e4\u010d\u0161inou pou\u017e\u00edva spolu s\u00a0list()<\/em>.<\/p>\n
Pr\u00edklad:<\/em><\/p>\n
<?php\r\nwhile (list($key,$value) = each($den))\r\n \u00a0echo $value.\",\";\r\n?><\/pre>\n
V\u00fdsledok pr\u00edkladu:<\/em><\/p>\n
Pondelok,Utorok,Streda,\u0160tvrtok,Piatok,Sobota,Nede\u013ea,<\/p>\n
Po vykonan\u00ed funkcie\u00a0each()<\/em>\u00a0bude kurzor po\u013ea ponechan\u00fd na \u010fal\u0161om prvku po\u013ea alebo na poslednom prvku, ak je na konci po\u013ea.<\/p>\n
Funkcia\u00a0list()<\/em>\u00a0(podobne ako\u00a0array()<\/em>) nie je v podstate funkcia, ale jazykov\u00e1 kon\u0161trukcia.\u00a0list()<\/em>\u00a0sa pou\u017e\u00edva na priradenie zoznamu premenn\u00fdch v jednej oper\u00e1cii.<\/p>\n
Pozn\u00e1mka:<\/strong>\u00a0list()<\/em>\u00a0funguje iba s \u010d\u00edseln\u00fdmi po\u013eami a preber\u00e1 \u010d\u00edseln\u00e9 indexy od\u00a00<\/em>.<\/p>\n
Pr\u00edklad:<\/em><\/p>\n
<?php\r\n$info = array('Kava', 'hneda', 'kofein');\r\n \/\/ V\u00fdpis v\u0161etk\u00fdch premenn\u00fdch\r\n list($drink, $farba, $sila) = $info;\r\n print \"$drink je $farba a $sila ju rob\u00ed \u0161peci\u00e1lnou.<br \/>\";\r\n\u00a0\/\/ V\u00fdpis niektor\u00fdch z nich\r\n list($drink, , $sila) = $info;\r\n print \"$drink ma $sila.<br \/>\";\r\n\u00a0\/\/ Alebo ponech\u00e1me iba tretiu\r\n list( , , $sila) = $info;\r\n print \"Potrebujem $sila!\";\r\n?><\/pre>\n
\u00a0V\u00fdsledok pr\u00edkladu:<\/em><\/p>\n
Kava je hneda a kofein ju rob\u00ed \u0161peci\u00e1lnou.
\nKava ma kofein.
\nPotrebujem kofein!<\/p>\n
Pre ka\u017ed\u00e9 pole existuje v PHP ukazate\u013e (kurzor), ktor\u00fd ukazuje na niektor\u00fd prvok po\u013ea. Funkcia\u00a0reset()<\/em>\u00a0prenesie tento ukazate\u013e na prv\u00fd prvok po\u013ea.<\/p>\n
Pr\u00edklad:<\/em><\/p>\n
<?php\r\n echo \"<br \/>\u010eal\u0161\u00ed v\u00fdpis:<br \/>\";\r\n while (list($key,$value) = each($den))\r\n \u00a0echo $value.\",\";\r\n echo \"<br \/>V\u00fdpis po resetovan\u00ed kurzora:<br \/>\";\r\n reset($den);\r\n while (list($key,$value) = each($den))\r\n \u00a0echo $value.\",\";\r\n?><\/pre>\n
V\u00fdsledok pr\u00edkladu:<\/em><\/p>\n
\u010eal\u0161\u00ed v\u00fdpis:
\nV\u00fdpis po resetovan\u00ed kurzora:
\nPondelok,Utorok,Streda,\u0160tvrtok,Piatok,Sobota,Nede\u013ea,<\/p>\n
Funkcia\u00a0current($pole)<\/em>\u00a0vracia hodnotu prvku po\u013ea\u00a0$pole<\/em>, na ktor\u00fd ukazuje ukazate\u013e.<\/p>\n
Podobne funguje aj funkcia\u00a0next()<\/em>, ktor\u00e1 najsk\u00f4r presunie ukazate\u013ena \u010fal\u0161\u00ed prvok po\u013ea a a\u017e potom vr\u00e1ti hodnotu prvku po\u013ea. Funkcia\u00a0prev()<\/em>\u00a0sa spr\u00e1va pr\u00e1ve tak ako\u00a0next()<\/em>, a\u017e no to, \u017ee vn\u00fatorn\u00fd ukazovate\u013e po\u013ea sa pos\u00fava sp\u00e4\u0165 a nie dopredu.<\/p>\n
Funkcia\u00a0key()<\/em>\u00a0vracia index prvku po\u013ea, na ktor\u00fd ukazuje ukazate\u013e.<\/p>\n
Funkcia\u00a0end()<\/em>\u00a0pos\u00fava vn\u00fatorn\u00fd ukazovate\u013e po\u013ea na posledn\u00fd prvok a vracia tento prvok.<\/p>\n
Pr\u00edklad:<\/em><\/p>\n
<?php\r\n reset<\/strong>($den);\r\n while(current<\/strong>($den))\r\n {\r\n echo \"Index: \".key<\/strong>($den);\r\n echo \"Hodnota: \".current<\/strong>($den);\r\n next<\/strong>($den);\r\n }\r\n?><\/pre>\n
\u00a0V\u00fdsledok pr\u00edkladu:<\/em><\/p>\n
Index: 1
\nHodnota: Pondelok
\nIndex: 2
\nHodnota: Utorok
\nIndex: 3
\nHodnota: Streda
\nIndex: 4
\nHodnota: \u0160tvrtok
\nIndex: 5
\nHodnota: Piatok
\nIndex: 6
\nHodnota: Sobota
\nIndex: 0
\nHodnota: Nede\u013ea<\/p>\n
 <\/p>\n
\u010eal\u0161ie pr\u00edklady asociat\u00edvnych pol\u00ed<\/p>\n
Pr\u00edklad:\u00a0<\/em>asociat\u00edvne pole \u010d.1<\/em><\/p>\n
$arr = array(\"foo\" => \"bar\", 12 => true);\r\necho $arr[\"foo\"].\"<br \/>\";\r\necho $arr[12];<\/pre>\n
\u00a0V\u00fdsledok pr\u00edkladu:<\/em><\/p>\n
bar
\n1<\/p>\n
Pr\u00edklad:<\/em>\u00a0asociat\u00edvne pole \u010d.2<\/em><\/p>\n
$arr1 = array(5 => 43, 32, 56, \"b\" => 12);\r\n$arr2 = array(5 => 43, 6 => 32, 7 => 56, \"b\" => 12);\r\necho $arr1[5].\"<br \/>\";\r\necho $arr1[6].\"<br \/>\";\r\necho $arr1[7].\"<br \/>\";\r\necho $arr1[b].\"<br \/>\";\r\necho \" <br \/>\";\r\necho $arr2[5].\"<br \/>\";\r\necho $arr2[6].\"<br \/>\";\r\necho $arr2[7].\"<br \/>\";\r\necho $arr2[b];<\/pre>\n
V\u00fdsledok pr\u00edkladu:<\/em><\/p>\n
43
\n32
\n56
\n12<\/p>\n
43
\n32
\n56
\n12<\/p>\n
PHP umo\u017e\u0148uje tie\u017e pr\u00e1cu s viacrozmern\u00fdmi po\u013eami:<\/p>\n
$a[1] = 1; \u00a0        \u00a0\u00a0\u00a0\u00a0\u00a0 \/\/ jednorozmern\u00e9 pole\r\n$a[1][1] = 1;\u00a0\u00a0      \u00a0\u00a0\u00a0\u00a0 \/\/ dvojrozmern\u00e9 pole,\r\nmatica$a[1][\"a\"][2] = 1;  \/\/ trojrozmern\u00e9 pole<\/pre>\n
Pr\u00edklad:<\/em>\u00a0jednoduch\u00e9 viacrozmern\u00e9 pole<\/em><\/p>\n
$arr = array(\"somearray\" => array(6 => 5, 13 => 9, \"a\" => 42));\r\necho $arr[\"somearray\"][6].\"<br \/>\";\r\necho $arr[\"somearray\"][13].\"<br \/>\";\r\necho $arr[\"somearray\"][\"a\"];<\/pre>\n
V\u00fdsledok pr\u00edkladu:<\/em><\/p>\n
5
\n9
\n42<\/p>\n
Pr\u00edklad:<\/em>\u00a0jednoduch\u00e9 viacrozmern\u00e9 pole<\/em><\/p>\n
$fruits = array(\"fruits\" => array(\"a\" => \"orange\",\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"b\" => \"banana\",\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"c\" => \"apple\"),\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"numbers\" => array(1,\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2,\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 3,\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 4,\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 5,\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 6),\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"holes\"\u00a0\u00a0 => array(\"first\",\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a05 => \"second\",\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \"third\")\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 );\r\necho $fruits[\"holes\"][5].\"<br \/>\";\r\necho $fruits[\"fruits\"][\"a\"].\"<br \/>\";\r\necho $fruits[\"holes\"][0].\" (pred zru\u0161en\u00edm)<br \/>\";\r\n\/\/ zru\u0161enie premennej\r\nunset($fruits[\"holes\"][0]);\r\necho $fruits[\"holes\"][0].\"(po zru\u0161en\u00ed)\";<\/pre>\n
V\u00fdsledok pr\u00edkladu:<\/em><\/p>\n
second
\norange
\nfirst (pred zru\u0161en\u00edm)
\n(po zru\u0161en\u00ed)<\/p>\n","protected":false},"excerpt":{"rendered":"
Medzi najz\u00e1kladnej\u0161ie funkcie pre pr\u00e1cu s po\u013eom patr\u00ed funkcia\u00a0count(). Funkcia\u00a0count($pole)\u00a0spo\u010d\u00edta po\u010det prvkov po\u013ea\u00a0$pole. Pr\u00edklad: <?php $den = Array(„1“ => „Pondelok“, \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 „2“ => „Utorok“, \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 „3“ => „Streda“, \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 „4“ => „\u0160tvrtok“, \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 „5“ => „Piatok“, \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 „6“ => „Sobota“, \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 „0“ => „Nede\u013ea“); for($i=0; $i<count($den); $i++) echo $den[$i].“<br \/>“; echo count($den); ?> V\u00fdsledok pr\u00edkladu: […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-373","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/gdm.sosthe.sk\/index.php?rest_route=\/wp\/v2\/pages\/373","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gdm.sosthe.sk\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/gdm.sosthe.sk\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/gdm.sosthe.sk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gdm.sosthe.sk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=373"}],"version-history":[{"count":1,"href":"https:\/\/gdm.sosthe.sk\/index.php?rest_route=\/wp\/v2\/pages\/373\/revisions"}],"predecessor-version":[{"id":374,"href":"https:\/\/gdm.sosthe.sk\/index.php?rest_route=\/wp\/v2\/pages\/373\/revisions\/374"}],"wp:attachment":[{"href":"https:\/\/gdm.sosthe.sk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=373"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}