What will be the output of the below JS code segment
x = { "a" : 1 };
y = "a";
x[y]++;
alert(x.a);

The third line takes the variable x, looks inside the value of that variable "y" .So now it will be x["a"]++
and a = 1. so the final expression becomes

x[y]++ => x["a"]++ => 1++ =>2