How to convert array to JSON in PHP?

',"'bar'",'"baz"','&blong&', "\xc3\xa9"); echo "Normal: ", json_encode($a), "\n"; echo "Tags: ", json_encode($a, JSON_HEX_TAG), "\n"; echo "Apos: ", json_encode($a, JSON_HEX_APOS), "\n"; echo "Quot: ", json_encode($a, JSON_HEX_QUOT), "\n"; echo "Amp: ", json_encode($a, JSON_HEX_AMP), "\n"; echo "Unicode: ", json_encode($a, JSON_UNESCAPED_UNICODE), "\n"; echo "All: ", json_encode($a, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP | JSON_UNESCAPED_UNICODE), "\n\n"; $b = array(); echo "Empty array output as array: ", json_encode($b), "\n"; echo "Empty array output as object: ", json_encode($b, JSON_FORCE_OBJECT), "\n\n"; $c = array(array(1,2,3)); echo "Non-associative array output as array: ", json_encode($c), "\n"; echo "Non-associative array output as object: ", json_encode($c, JSON_FORCE_OBJECT), "\n\n"; $d = array('foo' => 'bar', 'baz' => 'long'); echo "Associative array always output as object: ", json_encode($d), "\n"; echo "Associative array always output as object: ", json_encode($d, JSON_FORCE_OBJECT), "\n\n"; ?> 以上例程会输出： Normal: ["","'bar'","\"baz\"","&blong&","\u00e9"] Tags: ["\u003Cfoo\u003E","'bar'","\"baz\"","&blong&","\u00e9"] Apos: ["","\u0027bar\u0027","\"baz\"","&blong&","\u00e9"] Quot: ["","'bar'","\u0022baz\u0022","&blong&","\u00e9"] Amp: ["","'bar'","\"baz\"","\u0026blong\u0026","\u00e9"] Unicode: ["","'bar'","\"baz\"","&blong&","é"] All: ["\u003Cfoo\u003E","\u0027bar\u0027","\u0022baz\u0022","\u0026blong\u0026","é"] Empty array output as array: [] Empty array output as object: {} Non-associative array output as array: [[1,2,3]] Non-associative array output as object: {"0":{"0":1,"1":2,"2":3}} Associative array always output as object: {"foo":"bar","baz":"long"} Associative array always output as object: {"foo":"bar","baz":"long"}