php怎么接收json

	$.ajax({
		
       cache: true,
        type: "POST",
        url:"__URL__/index",   
        data:{name:$("#name").val()},
        async: false,
       datatype: "json",
        error: function(request) {
            alert("Connection error");
        },
      success: function(data) {
           
    
        }
    });