php和json的相互转换

json_encode()

<?php /*****一维数组*********///有键$arr = array(	'a'=>1, 	'b'=>2,	'c'=>3,);$json = json_encode($arr);echo($json);  //{"a":1,"b":2,"c":3}//无键$arr = array(1,2,3);$json = json_encode($arr);echo($json);  //[1,2,3]/*****二维数组*********///有键$arr = array(	'a' => array('id'=>1, 'xuefei'=>"100" ), 	'b' => array('id'=>2, 'xuefei'=>"200" ),	'c' => array('id'=>3, 'xuefei'=>"300" ),);$json = json_encode($arr);echo($json);  //{"a":{"id":1,"xuefei":"100"},"b":{"id":2,"xuefei":"200"},"c":{"id":3,"xuefei":"300"}}//无键$arr = array(	array('id'=>1, 'xuefei'=>"100" ), 	array('id'=>2, 'xuefei'=>"200" ),	array('id'=>3, 'xuefei'=>"300" ),);$json = json_encode($arr);echo($json);  //[{"id":1,"xuefei":"100"},{"id":2,"xuefei":"200"},{"id":3,"xuefei":"300"}]?>

json_decode

<?php /*****一维json*********///有键$json = '{"a":1,"b":2,"c":3}'; //不加key的话输出null$arr = json_decode($json);var_dump($arr);/*输出：object(stdClass)[1]  public 'a' => int 1  public 'b' => int 2  public 'c' => int 3*/ //无键$json = '["a","b","c"]';  //加key的话输出null$arr = json_decode($json);var_dump($arr);/*输出：array (size=3)  0 => string 'a' (length=1)  1 => string 'b' (length=1)  2 => string 'c' (length=1)*//*****二维json*********///有键$json = '{"a":{"id":1,"xuefei":"100"},"b":{"id":2,"xuefei":"200"},"c":{"id":3,"xuefei":"300"}}';$arr = json_decode($json,true);var_dump($arr);/*输出：array (size=3)  'a' =>     array (size=2)      'id' => int 1      'xuefei' => string '100' (length=3)  'b' =>     array (size=2)      'id' => int 2      'xuefei' => string '200' (length=3)  'c' =>     array (size=2)      'id' => int 3      'xuefei' => string '300' (length=3)*/ //无键$json = '[{"id":1,"xuefei":"100"},{"id":2,"xuefei":"200"},{"id":3,"xuefei":"300"}]';$arr = json_decode($json,true);var_dump($arr);/*输出：array (size=3)  0 =>     array (size=2)      'id' => int 1      'xuefei' => string '100' (length=3)  1 =>     array (size=2)      'id' => int 2      'xuefei' => string '200' (length=3)  2 =>     array (size=2)      'id' => int 3      'xuefei' => string '300' (length=3)*/ ?>