php json_encode 替代方法（亦可显示中文）

浏览数：37 / 时间：2015年06月09日

原文网址：http://justcoding.iteye.com/blog/974631

json_encode在ajax应用的开发里是必不可少的一个函数，但是json_encode的使用条件是比较苛刻的，需要在php 5.2.0以上并且需要PECL json在1.2.0以上才可以使用。

其实json_encode的替代方法在网上有很多，这里提供一个在php在线手册里看到的一个简单的函数，已经通过测试。

function jsonEncode($var) {
    if (function_exists(‘json_encode‘)) {
        return json_encode($var);
    } else {
        switch (gettype($var)) {
            case ‘boolean‘:
                return $var ? ‘true‘ : ‘false‘; // Lowercase necessary!
            case ‘integer‘:
            case ‘double‘:
                return $var;
            case ‘resource‘:
            case ‘string‘:
                return ‘"‘. str_replace(array("\r", "\n", "<", ">", "&"),
                    array(‘\r‘, ‘\n‘, ‘\x3c‘, ‘\x3e‘, ‘\x26‘),
                    addslashes($var)) .‘"‘;
            case ‘array‘:
                // Arrays in JSON can‘t be associative. If the array is empty or if it
                // has sequential whole number keys starting with 0, it‘s not associative
                // so we can go ahead and convert it as an array.
                if (empty ($var) || array_keys($var) === range(0, sizeof($var) - 1)) {
                    $output = array();
                    foreach ($var as $v) {
                        $output[] = jsonEncode($v);
                    }
                    return ‘[ ‘. implode(‘, ‘, $output) .‘ ]‘;
                }
                // Otherwise, fall through to convert the array as an object.
            case ‘object‘:
                $output = array();
                foreach ($var as $k => $v) {
                    $output[] = jsonEncode(strval($k)) .‘: ‘. jsonEncode($v);
                }
                return ‘{ ‘. implode(‘, ‘, $output) .‘ }‘;
            default:
                return ‘null‘;
        }
    }
}


echo jsonEncode(array(‘first‘=>‘testing‘,‘second‘=>‘tangjili‘));

或者用下面：

<?php

function php_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(‘php_json_encode‘, $data) ) . ‘]‘;
        else {
            $items = Array();
            foreach( $data as $key => $value ) $items[] = php_json_encode("$key") . ‘:‘ . php_json_encode($value);
            $json = ‘{‘ . implode(‘,‘, $items) . ‘}‘;
        }
    } elseif( is_string($data) ) {
        $string = ‘"‘ . addcslashes($data, "\\\"\n\r\t/" . chr(8) . chr(12)) . ‘"‘;

        $json    = ‘‘;
        $len    = strlen($string);
        for( $i = 0; $i < $len; $i++ ) {
            $char = $string[$i];

            $c1 = ord($char);
            if( $c1 <128 ) { $json .= ($c1 > 31) ? $char : sprintf("\\u%04x", $c1); continue; }
            $c2 = ord($string[++$i]);
            if ( ($c1 & 32) === 0 ) { $json .= sprintf("\\u%04x", ($c1 - 192) * 64 + $c2 - 128); continue; }
            $c3 = ord($string[++$i]);
            if( ($c1 & 16) === 0 ) { $json .= sprintf("\\u%04x", (($c1 - 224) <<12) + (($c2 - 128) << 6) + ($c3 - 128)); continue; }
            $c4 = ord($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 $json = strtolower(var_export( $data, true ));
    
    return $json;
}


echo php_json_encode(array(‘first‘=>‘testing‘));

如果想要现实中文可以结合下面的function

function arrayRecursive(&$array, $function, $apply_to_keys_also = false)
{
    foreach ($array as $key => $value) {
        if (is_array($value)) arrayRecursive($array[$key], $function, $apply_to_keys_also);
        else $array[$key] = $function($value);

        if ($apply_to_keys_also && is_string($key)) { $new_key = $function($key); if ($new_key != $key) { $array[$new_key] = $array[$key]; unset($array[$key]); } }
    }
}

例子：

function JSON($array) {
    arrayRecursive($array, ‘urlencode‘, true);
    $json = jsonEncode($array); // 或者 $json = php_json_encode($array);
    return urldecode($json);
}

echo JSON(array(‘first‘=>‘testing‘,‘second‘=>‘中文‘));