if statement is being executed even when the condition is false

while executing the code only if statements are being executed even when the condition is false.

I tried DEBUGGING and the condition i'm giving is definitely giving a false back but not sure why

 if (
    $("#ship-to-different-address-checkbox").length != 0 &&
    $(".shipping_address").length == 0
  ) {
    postcode = $("#shipping_postcode").val();
  } else {
    postcode = $("#billing_postcode").val();
  }