今天coding时,需要将php中的变量返回给第三方,第一个想到就是使用json格式,方便易用。于是用了json_encode,但是发现居然报语法错误,查了手册才发现,json_enode 是在5.2.0才作为标准扩展加入php的,而我们的机器上php的版本是5.1.6,原来该扩展还未加进来。由于这个应用比较小,而且本人赖得升级php的版本,而且再手工安装这个扩展也比较麻烦,所以想到了使用php实现json_encode,原理上应该不难,找到一段代码,共享之~
代码如下:
<?php function __json_encode( $data ) { if( is_array($data) || is_object($data) ) { $islist = is_array($data) && ( empty($data) || array_keys($data) === range(0,count($data)-1) ); if( $islist ) { $json = '[' . implode(',', array_map('__json_encode', $data) ) . ']'; } else { $items = Array(); foreach( $data as $key => $value ) { $items[] = __json_encode("$key") . ':' . __json_encode($value); } $json = '{' . implode(',', $items) . '}'; } } elseif( is_string($data) ) { # Escape non-printable or Non-ASCII characters. # I also put the \\ character first, as suggested in comments on the 'addclashes' page. $string = '"' . addcslashes($data, "\\\"\n\r\t/" . chr(8) . chr(12)) . '"'; $json = ''; $len = strlen($string); # Convert UTF-8 to Hexadecimal Codepoints. for( $i = 0; $i < $len; $i++ ) { $char = $string[$i]; $c1 = ord($char); # Single byte; if( $c1 <128 ) { $json .= ($c1 > 31) ? $char : sprintf("\\u%04x", $c1); continue; } # Double byte $c2 = ord($string[++$i]); if ( ($c1 & 32) === 0 ) { $json .= sprintf("\\u%04x", ($c1 - 192) * 64 + $c2 - 128); continue; } # Triple $c3 = ord($string[++$i]); if( ($c1 & 16) === 0 ) { $json .= sprintf("\\u%04x", (($c1 - 224) <<12) + (($c2 - 128) << 6) + ($c3 - 128)); continue; } # Quadruple $c4 = ord($string[++$i]); if( ($c1 & 8 ) === 0 ) { $u = (($c1 & 15) << 2) + (($c2>>4) & 3) - 1; $w1 = (54<<10) + ($u<<6) + (($c2 & 15) << 2) + (($c3>>4) & 3); $w2 = (55<<10) + (($c3 & 15)<<6) + ($c4-128); $json .= sprintf("\\u%04x\\u%04x", $w1, $w2); } } } else { # int, floats, bools, null $json = strtolower(var_export( $data, true )); } return $json; } ?>