I was evaluating the various ways in which the big guys implement auto suggest. These are my observations.(Search string used was “ab”) Questions towards the end.

Yahoo tries something like this, where the response was a JSONP. Response is readable and serves the purpose.

Yahoo’s response

yasearch({"q":"ab ","gprid":"Y435dN7TRFqnYqQhnBueJA","f":["k","m"],"r":[["ab de villiers",0],["ab exercises",0],["ab king pro",0],
["ab infi-net internet banking",0],["ab mujhe raat din",0],["ab workouts",0],["ab mp3",0],["ab meri bari",0],["ab ke baras",0],["ab meri baari",0]]})

Bing had a similar approach. Returns an “if” block, sa_inst.apiCB() seems to be a function which would process the JSON. Again response is readable and legit.

Bing’s response

if(typeof sa_inst.apiCB == 'function') sa_inst.apiCB({"AS":{"Query":"ab","FullResults":1,"Results":[{"Type":"AS","Suggests": [{"Txt":"ab<strong>p</strong> <strong>news</strong>","Type":"AS","Sk":""}, 
{"Txt":"ab<strong>bottapp</strong>.ab<strong>bott</strong>.<strong>in</strong>","Type":"AS","Sk":"AS1"},{"Txt":"ab<strong>t</strong> <strong>travels</strong>","Type":"AS","Sk":"AS2"},{"Txt":"ab<strong>p</strong> <strong>ananda</strong>","Type":"AS","Sk":"AS3"},
{"Txt":"ab<strong>hibus</strong>","Type":"AS","Sk":"AS4"},{"Txt":"ab<strong>p</strong> <strong>maza</strong>","Type":"AS","Sk":"AS5"},  {"Txt":"ab<strong>b</strong>","Type":"AS","Sk":"AS6"},
{"Txt":"ab<strong>outgoogle</strong>","Type":"AS","Sk":"AS7"}]}]}} /* pageview_candidate */);

Now comes Google. Response is sent as 2 JSON objects(separated by /””/). Most of it is unreadable.

Google’s response

{e:"XteVUYKqDoKHrAfdz4D4Aw",c:0,u:"https://www.google.com/s?hlx3denx26gs_rnx3d14x26gs_rix3dpsy-abx26tokx3dvsobDhICRmdcnY7ayKTGngx26cpx3d2x26gs_idx3ddx26xhrx3dtx26qx3dabx26es_nrsx3dtruex26pfx3dpx26outputx3dsearchx26sclientx3dpsy-abx26oqx3dx26gs_lx3dx26pbxx3d1x26bavx3don.2,or.r_cp.r_qf.x26bvmx3dbv.46751780,d.bmkx26fpx3d2647af89de6b6c61x26biwx3d1366x26bihx3d453x26tchx3d1x26echx3d2x26psix3dVteVUcYuzOGsB6LpgdgB.1368774484351.1",p:true,d:"[x22abx22,     
[[x22ab\u003Cb\u003Ec\u003C\/b\u003Ex22,0,[]],[x22ab\u003Cb\u003Ec news\u003C\/b\u003Ex22,0,[]],[x22ab\u003Cb\u003Eercrombie\u003C\/b\u003Ex22,0,[]],[x22ab\u003Cb\u003Ecya\u003C\/b\u003Ex22,0,[]]],
{x22jx22:x22dx22,x22qx22:x22t8z6h8KhWvbkEX6xablxgYxDUq4x22,x22tx22:
{x22bpcx22:false,x22tlwx22:false}}]"}
/*""*/
{e:"XteVUYKqDoKHrAfdz4D4Aw",c:-1,u:"https://www.google.com/searchdata?hlx3denx26gs_rnx3d14x26gs_rix3dpsy-abx26tokx3dvsobDhICRmdcnY7ayKTGngx26cpx3d2x26gs_idx3ddx26xhrx3dtx26qx3dabx26es_nrsx3dtrue
x26pfx3dpx26outputx3dsearchx26sclientx3dpsy-abx26oqx3dx26gs_lx3dx26pbxx3d1x26bavx3don.2,or.r_cp.r_qf.x26bvmx3dbv.46751780,d.bmkx26fpx3d2647af89de6b6c61x26biwx3d1366x26bihx3d453x26tchx3d1x26echx3d2x26psix3dVteVUcYuzOGsB6LpgdgB.1368774484351.1",
p:true,d:"{x22snpx22:1}"}
/*""*/

1. Are those hex codes or what do you call them?
2. Why is there a need for 2 objects to be returned?
3. What is the need for encoding the JSON?
4. Which is the ideal format for JSON among these three?

Any thoughts on this are welcome.