json_decode to array in php not working code example

Example 1: parse json phph

echo json_decode("[1,2,3]")[0];

Example 2: php json decode not working on array

//"[{\"name\": \"bill\", \"score\": 0.7948127388954163}, {\"name\": \"john\", \"score\": 0.782698392868042}]";
//for json in above format try this
$r=json_decode(stripcslashes(trim($response,'"')));