Check if a key exists inside a json object

Question

amt: \"10.00\"
email: \"sam@gmail.com\"
merchant_id: \"sam\"
mobileNo: \"9874563210\"
orderID: \"123456\"
passkey: \"1234\"

The above is the JSON o

Answer 1

Try this,

if(thisSession.hasOwnProperty('merchant_id')){

}

the JS Object thisSession should be like

{
amt: "10.00",
email: "sam@gmail.com",
merchant_id: "sam",
mobileNo: "9874563210",
orderID: "123456",
passkey: "1234"
}

you can find the details here

Answer 2

You can try if(typeof object !== 'undefined')

Answer 3

I change your if statement slightly and works (also for inherited obj - look on snippet)

if(!("merchant_id" in thisSession)) alert("yeah");

var sessionA = {
  amt: "10.00",
  email: "sam@gmail.com",
  merchant_id: "sam",
  mobileNo: "9874563210",
  orderID: "123456",
  passkey: "1234",
}

var sessionB = {
  amt: "10.00",
  email: "sam@gmail.com",
  mobileNo: "9874563210",
  orderID: "123456",
  passkey: "1234",
}


var sessionCfromA = Object.create(sessionA); // inheritance
sessionCfromA.name = 'john';


if (!("merchant_id" in sessionA)) alert("merchant_id not in sessionA");
if (!("merchant_id" in sessionB)) alert("merchant_id not in sessionB");
if (!("merchant_id" in sessionCfromA)) alert("merchant_id not in sessionCfromA");

if ("merchant_id" in sessionA) alert("merchant_id in sessionA");
if ("merchant_id" in sessionB) alert("merchant_id in sessionB");
if ("merchant_id" in sessionCfromA) alert("merchant_id in sessionCfromA");