jQuery Ajouter le nombre comme variable ID

You need to add parenthesis () for priority to evaluate add loopVar first. If your variable contains numeric value then do not need to apply parseInt function.

loopVar = "1";
alert('#imgAvatar'+(parseInt(loopVar)+1));

OR

loopVar = 1;
alert('#imgAvatar'+ (loopVar+1) );
Splendid Salmon