L'API Facebook retourne null, comment l'ignorer en Javascript

Question

Ce code fonctionne bien s'il n'y a pas de valeurs nulles retournées. Mais j'ai remarqué au cours des tests que si une valeur est nulle, alors elle jette et erreur et casse le reste du script.

Comment puis-je ignorer la valeur si null ou la définir sur autre chose?

function fqlQuery(){ 
       FB.api('/me', function(response) { 
        var query = FB.Data.query('SELECT uid, first_name, last_name, email, sex, pic_square, timezone, birthday_date, current_location FROM user WHERE uid = me()', response.id); 
        query.wait(function(rows) { 
         fb_uid = rows[0].uid; 
         first_name = rows[0].first_name; 
         last_name = rows[0].last_name; 
         sex = rows[0].sex; 
         email = rows[0].email; 
         fb_pic_square = rows[0].pic_square; 
         timezone = rows[0].timezone; 
         birthday_date = rows[0].birthday_date; 
         current_city = rows[0].current_location.city; 
         current_country = rows[0].current_location.country; 
         $.ajax({ 
          type: "POST", 
          url: "postdb.php", 
          data: "first_name=" + first_name + "&last_name=" + last_name + "&email=" + email + "&fb_uid=" + fb_uid + "&sex=" + sex + "&fb_pic_square=" + fb_pic_square + "&timezone=" + timezone + "&birthday_date=" + birthday_date + "&current_city=" + current_city + "&current_country=" + current_country, 

    success: function(msg){ 
    alert("Data Saved: " + msg); 
    } 

         }); 



        }); 

       }); 

merci d'avance.

Answer 1

var foo = rows[0].foo || ""; 

renverra "" (une chaîne vide) si rows[0].foo est nulle.

Answer 2

Je l'ai réparé comme ça.

if(rows[0].current_location != null){ 
    current_city = rows[0].current_location.city || ""; 
    current_country = rows[0].current_location.country || ""; 
}